Ai de Asobu. 

Anthology of one-shots by Ninomiya Hikaru. Includes: 1. Gomennasai 2. Bousou Kiss 3. ...Gokko A brother and sister play an incestuous game where they do perverted things to each other until one gives up. The game ends with intercourse. 4. Otoshigoro 5. One Step 6. Kanransha (Ferris Wheel) After being suddenly confessed to by Takahara-kun, Sudo-san makes love to him. However, Takahara-kun is moving the next day and now she has to deal with a long-distance relationship. 7. Yume musubi to 8. Hakuchu yamu 9. Yoshi × Yoshi 10. Only One Izumi Taeko is a weird and flighty girl, rumor has it you’ll only need a coin to get your way with her, but is this true? 11. Reset