Bocchan, Oikomi Ai desu yo.

"Hiyori-kun, I need your help with the final mission, and that is—"
Hiyori's part-time coworker, the delinquent high schooler Rennosuke, is full of contradictions. One moment, he's furiously sketching adorable drawings with a terrifying expression, the next, he's silently petting an "imaginary cat" when no one's around…
Hiyori has always wanted to befriend Rennosuke, but he hasn't even managed a proper conversation with graduation approaching.
Then, one day, by sheer coincidence, he finally gets to talk to him! Overjoyed, Hiyori thinks he's finally making progress—
But wait!!! What is even happening right now—!?!?!?

(Source: Tokyomangasha, translated)

Note: Includes one extra chapter.