Satoi Kanojo: Itoshii Kono Ko wa Ore no Tsugai

Office worker and Omega, Kaede, was on his way home from work, excited to see his girlfriend, Hotaru, an Alpha, after a long time. Unexpectedly, his heat cycle begins as he reaches the door of his apartment. According to his heat cycle app, it should come much later, but...

His muddy feelings and his excitement — Hotaru can see through all of it.

(Source: DLsite, translated)