Nigeta Hitsuji no Tsukamaekata
Complete | AOYAMA Toomi | 2000 released
Guy 1: Solved a maths question. Won one million $. Now hides himself away (recluse). So far: Journalist guy 2 - figured out where 1 is. Got himself drunk/sick, and dropped off at 1's house. Found out that 1 has horns. Integrated himself into the house. Attempting to seduce the herbivore guy into getting an article (also 1 has a younger guy (son? nah but that kinda age) with him too).
Kimi De Oboreta Ato Wa