Gozen 0-ji no Amai Wana

When Kouki enters college, he reunites with Rei, his best friend from middle school, and ends up sharing a room with him. Rei takes care of the lazy Kouki without looking bothered by it. For Rei, who was once the target of bullying, Kouki is the hero who saved him from rock bottom. Kouki thought that him and Rei were dear friends, but he's sometimes confused by Rei's obsessive feelings towards him...?

(Source: Kaiohsha, translated)