Gakuen Heaven: Shichijo - Sweet Sweet Darling!

Synopsis

Even though Keita and Omi have been going steady for a month, Keita's worried how he can never seem to read his allusive and cunning lover. So when Omi starts acting even stranger than usual, Keita decides to get to the bottom of it and find out more about him. But he winds up biting off more than he can chew when he gets caught up in a high-stakes conspiracy involving Omi's genius-hacker father...

(Source: Blu Manga)

An alternative retelling of Gakuen Heaven, based on the Shichijou route of the original visual novel.