Ozu-kun no Vita Sexualis

1-3. Ozu-kun no Vita Sexualis (小津くんのヰタ・セクスアリス); Canna Vols. 9, 14, 16

30-year-old Ozu is feeling left out. His friends are slowly marrying off and with his tiny salary as a video store clerk, he can't afford to go on trips with them when they can all hang out. Oh, and just to top it all off, his popular friend Araragi just found out Ozu's most embarrassing secret… Ozu's still a virgin at 30, but maybe it's not so bad after all, because Araragi's never been with a girl either?

(Source: Kadokawa, translated)

4-5. Himitsu no Aru Futari (秘密のある二人); Cab Vols. 1, 3

6. 17 (17 セブンティーン); Cab Vol. 4