Toshiue no Anata

Until a few weeks ago, Takaya had not seen his cousin Saki in years. But when his parents left on a trip, he was left in her care. That same night, Saki had a few too many drinks and the two of them ended up sleeping together for the first time. But recently things have not been going well with his new girlfriend—at least from his perspective—as Saki constantly gets hit on whenever they go out, leaving Takaya frustrated and unsure about her feelings towards him.