Kareshi Tokidoki Kanojo

The romantic comedy centers on Hodaka Akizuki, a 17-year-old high school boy, who falls in love with the school madonna Chihaya Shishizaki. Hodaka bravely confesses to Chihaya, and they officially become a couple. But Chihaya actually keeps an unimaginable secret, even from her boyfriend Hodaka.

(Source: Anime News Network, edited)