She attends the same high school, Makuhari Shuuei High School, as Tomoko, though Tomoko had more or less completely forgotten about her. She has had a crush on Tomoki for a number of years, and she blames Tomoko for seemingly ruined her chances of being with him.
Kotomi was a middle school classmate of Yū and Tomoko. When introduced in the manga, Kotomi has a strong dislike for Tomoko which stems from Tomoko comically ruining her attempt to be introduced to Tomoki. For her part, Tomoko appears to have forgotten about her. The spin-off manga TomoMote which takes place during their middle-school years shows that she and Tomoko always clashed over attention from Yū, though the animosity appeared initiated by Tomoko.
Over the course of the story, she and Tomoko often clash over reasons played for comedy. Since Tomoko does not really understand relationships, she plays with Kotomi's crush for her brother. Yū brings them together in a few chapters, and in the most recent ones they have developed a sort of détente though Tomoko still becomes enraged when reminded of Kotomi's crush. Kotomi does have other friends who support her, including one who also has a crush on Tomoki: Akari Iguchi. Her most consistent friend who tries to moderate her behavior when it comes to jealousy over any girl who she imagines also has a crush on Tomoki is Hikari Itō.
Kotomi is a shy girl but does not have the same difficulty with social interactions that Tomoko has. If given the chance, she will willingly pontificate upon baseball and her favorite team to anyone. Much of her character is depicted reacting to Tomoko, making her appear resentful, judgmental, and jealous. However, she appears a much nicer person to other people. Despite her sometimes petty-level rivalry with Tomoko, she does not truly hate her. She can also become friends with her potential rival for Tomoki such as Akari.
In more recent chapters, Kotomi has grown less tolerant of any imagined rival for Tomoki. She very publicly accuses Yoshida of being a "slut" in the cafeteria when she sees her with her arm around Tomoki. When she meets Kii, she immediately panics that since a cousins can legally marry, Kii will become a rival. When she overhears Shizuku Hirasawa ask Tomoko which soccer player is her brother during a match, she directly insults her.
When Tomoki asks Itō about Kotomi, Itō responds with a long rambling description to the irritation of Tomoki. Aside from Kotomi's devotion to the Chibi Lotte Marines, Itō reveals that while Kotomi is sociable, she tends to keep her distance from others, and she always uses the last name with the -san suffix.
Chapter 150 provides considerable insight into Kotomi’s social difficulties. Like Tomoko’s, they are largely self-made. At a softball game during the sports tournament, Kotomi takes charge and proceeds to alienate everyone on both sides by treating the friendly and casual event with deadly seriousness. She bosses the other players and uses frustrating moves like squeeze plays. Itō describes the situation: “Koto’s going all out, despite knowing it will earn her enmity from allies and opponents alike. You’re amazing, Koto!”
Kotomi has shoulder-length black hair. Her main accessory are her glasses. Her dress varies from her middle and high school uniforms to more contemporary clothes outside of school. In high school, she mainly wears a sweater-vest over her shirt and tie with skirt. She dresses in her favorite team's gear when attending baseball games.
- Season 1: Episode 13 (OVA)
- Volume 05: Chapter 46
- Volume 06: Chapters 47, 48, 50, 52, 54, 55, Omake
- Volume 07: Chapters 57, 64, 65
- Volume 08: Chapters 71, 74
- Volume 09: Chapters 78, 79, 83, 84,
86, 88, Special
- Volume 10: Chapters 89, 91, 93, Special, Omake
- Volume 11: Chapters 100, 101, 106, 108, Special
- Volume 12: Chapters 112, 113, 117, 122
- Volume 13: Chapters 123, 124, 128
- Volume 14: Chapters 133, 134, 135, 136, 141, 142
- Volume 15: Chapters 143, 144, 145, 150, Omake
- Volume 16: Chapters 151, 153, 154, 155, 157
- TBA: Chapter 159, 162, 163, 164
- Volume 01: Chapters 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28
- 10th Anniversary
Strikethrough episodes or chapters indicate the character was mentioned but did not make a physical appearance)
Yū ends up befriending Kotomi in middle school on a day when Tomoko had to stay home due to fever. The two have since been close and have kept in touch after reuniting. Yū initially seems oblivious to the discord between Kotomi and Tomoko. She then works to bring them together. For their part, the two sort of agree to be civil for Yū's sake.
Kotomi is introduced in the manga as holding a deep seated grudge against Tomoko, considering her a "bitch" and "human trash." Part of this comes from the shared rivalry for the friendship of Yū; the other part comes from Kotomi's crush on Tomoko's brother. Tomoko comically ruins an introduction between the two in middle school, and Kotomi has carried her resentment ever since. While Tomoko initially appears oblivious to Kotomi's feelings for her brother, she subsequently uses Kotomi's crush as an opportunity to torment her. In Chapter 83 when Kotomi reacts to learning that a girl has been visiting Tomoko's brother for some time, only to relax a bit when Tomoko tells her the girl has never entered her home farther than the entry way, Tomoko calmly teases Kotomi by saying, "Though they usually have sex in the entry way before she leaves." In Chapter 89, she rewards Kotomi by allowing her into Tomoki's room for thirty minutes to do whatever she wants. In Chapter 106, Kotomi touches Tomoki on his shoulder, and Tomoko will later tease Kotomi that she later did "that" to herself with her hand. In Chapter 108 when Tomoki asks her about Kotomi, Tomoko describes her as a "raging pervert."
The spin-off manga TomoMote reveals that the two always had a bad relationship. Each begin to interpret any utterance or action by the other as an insult. Thus, in Chapter 15 when Tomoko complains about sweating in the humidity, Kotomi offers her deodorant which Tomoko immediately interprets as Kotomi stating she stinks. The two share common anime and manga interests but this does not bring the two closer as Tomoko initially ridicules that only kids watch cartoons. Tomoko does not remember Kotomi when she meets her in high school which further angers her former classmate. Further, Tomoko seems to make an effort to never remember her surname. While Kotomi does not appear in the broadcast anime, the OVA depicts their bitter rivalry for the attention of Yū.
As of recent chapters however, Kotomi's relationship with Tomoko has become more tolerant if not friendly, although they possibly do not realize this and would not admit it if they did. The changes start in Chapter 52 when Yū decides the trio should spend the first day of summer break together. They run into each other at the bus stop and agree to go together to meet Yū in a cafe and, while the ensuing ride was obviously awkward, there was no antagonism between the girls. During the rest of the day, Kotomi and Tomoko end up paying more attention to each other than to Yū herself, which leads her believe the duo to be great friends because they go to the same school.
In Chapter 64, Kotomi spends August 4th catching bugs with Yū and Tomoko despite her declaring the activity both childish and gross. However, after Tomoko convinces Yū that a rhinoceros beetle is "cute" and she should keep it as a pet, Kotomi quietly catches a centipede which she keeps on her desk at home. On August 10th, the trio goes to a polluted beach which Tomoko chose because it is close. During this "beach trip," Yū becomes emotional over the time they are spending together and starts to cry, which causes the other two girls to panic. On August 17, the trio heads over to Comiket, but Kotomi is soon left alone when the other two girls leave the place for it being "full of guys" and "stinking," although Tomoko tells Kotomi to call them when she's done. Kotomi seems to genuinely enjoy the time spent with Yū and Tomoko, as the only antagonism between her and Tomoko, open or otherwise, is during August 4th, but it's hard to say whether it actually meant something.
In Chapter 79, however, they seem to go back to being enemies. After Kotomi and Itō discover Tomoko alone during the school trip to Kyoto, she asks Itō if Tomoko can join them in what Tomoko describes as an condescending tone. Tomoko immediately spots her roommates and, in order to get away from Kotomi, joins them in exploring the city, which prompts Kotomi to follow her around, surprised that Tomoko actually has friends, much to Itō's confusion.
All in all, Kotomi and Tomoko seem to have a hate-like relationship, in one moment genuinely enjoying each other's presence and in another being at each other's throats. Simply put, their relationship developed from simply hating each other to being "frenemies," which was prompted by Yū's suggestion that they should get along in Chapter 54.
Kotomi has had a crush on Tomoki since she was in middle school. In Chapter 47 Tomoko embarrassed Kotomi by telling Tomoki that the girl wanted to see his dick, as a result of misunderstanding that Kotomi wanted to give him chocolate, not see his cock.
After she meets Tomoko again in Chapter 46, her one-sided crush on Tomoki continues. Much of the story at this stage involves a comic rivalry for his attention between her and Akari, both of whom Tomoko deems "perverts" and addresses them as "the dick sisters." Yet out of the blue in Chapter 108, Tomoki approaches first Tomoko then Akari to learn what type of person she is. In Chapter 112 she is comfortable enough to make and present him with chocolates with hilarious results.
One of Kotomi's treasures is the pictures she took of Tomoki during the school sports meet, especially the ones when, as a member of the soccer team, he had to wear a baseball uniform. That picture serves as her phone's wallpaper, which Tomoko later discovers to her irritation.
Tomoki seems to think of Kotomi as a strange person and does not seem to know much about her. He is usually confused by her weird antics and unusual bashful behavior around him. He does ask Tomoko about her, to Kotomi's delight, but other than greeting her, he does not pursue any relationship with her. In Chapters 133 and 134 she screams at Masaki Yoshida when she puts her arm around Tomoki. The scene comically and tragically degenerates, causing embarrassment to all involved. Kotomi knows she appears foolish to Tomoki, but she cannot help herself even though she ignites the wrath of "the delinquent." Tomoki finds the entire encounter irritating and embarrassing.
Itō often appears with Kotomi. In Chapter 117 Itō states that they have been friends for two years as of that point. She is aware of Kotomi's crush on Tomoki; in Chapter 133 she inwardly notes that Kotomi has "creeped out" classmates when she angrily over-reacts to Yuri mentioning she met Tomoki and even touched him once. She then watches Kotomi challenge Yoshida and tries to separate them. When Tomoki asks her about Kotomi, she responds with a Wall of Text.
A classmate of Kotomi, Akari also has a crush on Kotomi. Due to various comic incidents involving Kotomi and Tomoko arguing about how the latter told her brother that Kotomi wanted to see his genitals, Akari loses her senses and publicly proclaims she wants to see them "too!" Tomoko will refer to the two as "The Dick Sisters." Comedy aside, Akari seems to accept Kotomi's crush and remains her friend and even encourages her to pursue Tomoki even though it hurts her. Thus, she encourages and helps Kotomi to make chocolates to give to Tomoki. For her part, Kotomi is aware of her crush and occasionally feels guilty that any slight progress she makes with Tomoki may hurt Akari.
Until Chapter 133 they have little, if any, interaction. However, in the cafeteria when she sees Yoshida put her arm around Tomoki's neck she screams at Yoshida. Realizing that she has made a mistake, and none of Yoshida's friends which include Tomoko, Hina, and others will intercede to hold her back, she tries to apologize, but when Yoshida relaxes and begins chatting, if not slightly flirting, with Tomoki, she explodes again accusing Yoshida of being a "slut." Due to a humorous misunderstanding when Tomoki and Itō try to keep them apart and Yoshida walks into Tomoki's hand so that he ends up clutching her breast, Kotomi accuses Yoshida of letting Tomoki "grope" her which finally provokes Yoshida to drop her with a punch to her stomach.
Despite that, the two do not currently have further conflicts. Kotomi manages Yoshida during the intramural baseballtournament. However, Yoshida has not forgotten, and she refers to Kotomi as "Crazy Glasses" (イカレメガネ・ikare megane) to Tomoko and Itō when Tomoko reveals Kotomi's name to her.
Kotomi overhears Shizuku excitedly ask Tomoko which soccer player is Tomoki during a match. Kotomi angrily and obviously takes her picture with her phone then explains she took the picture since it is so unusual to see "pigs (ブタ・buta)" talk. Whether or not Kotomi will remember Shizuku or will just add her to her ever-growing collection of imagined rivals remains to be seen.
- Kotomi is an anagram of Tomoki.
- Her birthday is November 21st.
- Kotomi is a devoted fan of baseball and the Chiba Lotte Marines baseball team.
- Her phone wallpaper is a picture of Tomoki in the baseball uniform he had to wear during the school games.
- According to Chapter 122, Kotomi loves to read.
- "People should recognize that some girls are just nipples and nothing else." - TomoMote Chapter 6.
- "That fucking bitch! She's trash, just like I thought!!" - about Tomoko from Chapter 46
- "Ah, this feeling again... It's just like the first time we talked to each other when Naruse-san/Yū-chan wasn't around. That's right... I never really wanted to get along with this person to begin with. But we just ended up trying to get along back then too." - on Tomoko Chapter 54
- "Though she's sociable at heart, she tends to keep her distance from people. Especially when it comes to those she doesn't know well, she'll always use their last name and add -san to it. Though sometimes she snaps and does things that creep everyone else out. In fact, last year. . . ." - Hikari Itō, describing Kotomi to Tomoki Kuroki
|Female Characters||Tomoko Kuroki | Shiki Futaki | Anna Haruna | Shizuku Hirasawa | Akari Iguchi | Hikari Itō | Megumi Imae | Asuka Katō | Kayo | Kotomi Komiyama | Mrs. Kuroki | Koharu Minami | Miyazaki | Yū Naruse | Hina Nemoto | Ogino | Akane Okada | Reina | Fūka Sasaki | Kiko Satozaki | Sayaka | Yuri Tamura | Mako Tanaka | Emiri Uchi | Masaki Yoshida|
|Male Characters||Tomoki Kuroki | Aomatsu | Art Teacher | Hatsushiba | Homeroom Teacher | Jun Ishimine | Kakinuma | Yoshinori Kiyota | Kosaka | Mr. Kuroki | Suzuki | Nico Tanigawa | Wada | Yocchan|
|Minor and Unnamed||Minor and Unnamed Recurring Characters|
|Manga Volumes||01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14 | 15 | 16|
|Anime Episodes||01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | OVA|