Seven Days
Bright and early one Monday morning, Shino Yuzuru asks Seryou Touji out on a lark when they run into each other at the school gate. Seryou, who's immensely popular, has the odd habit of going out with anyone who asks him out first at the beginning of the week, then promptly dumping them at the end of it. "Anyone" apparently includes male upperclassmen like Shino, and as a boyfriend, Seryou is perfect--unfailingly thoughtful and kind. Shino, obviously, has no intention of being in a serious relationship with Seryou.
Oni Ni Hatsujou
When Tanami Riku's father died in a traffic accident, he was left all alone. Then suddenly a guy named Onikubo Nagi came and demanded to be his guardian in place of his father, who was actually Nagi's former teacher.
Hatsukoi Wa Gunjou Ni Tokeru