Spell (2003)

Blurb:
Second-year college student Takamasa Natori isn’t fond of date parties. For the most part, he finds the women pretentious and the whole concept a complete waste of time. But when his long time friend Takeda needs a favor, he finds himself being dragged to yet another one. This party ends up being a little different when he meets Junpei Kisugi. Kisugi is an old friend of Takeda and the two hit it off immediately. Unfortunately, Kisugi currently has a lover, Tooru; and Natori finds himself falling deeper and deeper under Kisugi’s spell. Can Natori bring himself to confess his feelings?

Source: www.anisearch.com/manga/788