Aisareta no ga Un no Tsuki

Ito, who has a low alcohol tolerance, finds himself meeting the notorious troublemaker Mao at a bar. For reasons beyond his understanding, Mao takes a liking to him, and they end up drinking together. However, Kaito gets drunk far too easily and is taken home by Mao. When he wakes up, it’s clear that something happened between them—and to make matters worse, he’s wearing a collar around his neck! Although he manages to escape that time, Mao seems strangely attached to him, refusing to leave him alone…!?

(Source: Core Magazine, translated)

Note: Includes one extra chapter.