Kosaka appears to be a rather gentlemanly and kind person. He also appears to be smart, as he was seen tutoring an unnamed girl who was assumed to be his girlfriend.
In Episode 3 Tomoko encounters him and a friend as she waits out a rain storm at a bus stop after her umbrella broke. She tries to impress them, fails as only Tomoko can, then leaves briefly to compose herself. When she returns, she finds them gone, When she falls asleep, Kosaka returns having bought Tomoko an umbrella. In Episode 8, Tomoko meets him again. Her cousin, Kiko Satozaki, believes him to be Tomoko's boyfriend after Tomoko's lengthy lie. When Kii finds him with a girl she demands an apology for hurting Tomoko. Discovering this, Tomoko requests that she be left alone with him and very formally apologizes. Kii sees this from a distance, realizes that Kosaka is not Tomoko's boyfriend, and begins treating Tomoko differently.
Nearly two years and one hundred and twenty chapters later, Kosaka reappears in the manga. In Chapter 163 after expressing her wish to Yuri and Mako that she get a boyfriend as they walk home, she walks into Kosaka who is returning home from college. He remembers Tomoko and greets her and asks about her "sister."
Kosaka has a thin build, gray eyes, pale skin, and short black hair.
- Volume 1: Chapter 5
- Volume 2: Chapter 15
- Volume 7: Chapter
- Volume 12: Chapter
- Volume 17: Chapter 163
Strikethrough episodes or chapters indicate the character was mentioned but did not make a physical appearance)
Kosaka has reached out to Tomoko to show her some kindness. After Tomoko formally apologizes for claiming to Kii that he was her boyfriend, he did not appear again in the manga until Chapter 163 where he runs into her on a street and greets her. He ask Tomoko how her "sister" is doing; Tomoko does not correct him that Kii is actually her cousin.
- The surname Kosaka means "small" (小) (ko) and "slope, hill" (坂) (saka).
- Kosaka is older than Tomoko and attends college when he reappears in the manga.
- A Makoto Kosaka played for the Chiba Lotte Marines, and a coach for the team.
|Female Characters||Tomoko Kuroki | Shiki Futaki | Anna Haruna | Shizuku Hirasawa | Akari Iguchi | Hikari Itō | Megumi Imae | Asuka Katō | Kayo | Kotomi Komiyama | Mrs. Kuroki | Sachi Mima | Koharu Minami | Miyazaki | Miho Narita | Yū Naruse | Hina Nemoto | Ogino | Nagi Ōtonari | 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||1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22|
|Anime Episodes||1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | OVA|