Suteneko No Karute
From Shinmakoku Scanlations: Kaoru is frustrated. He's just been dumped, again. And it's all because he could never express his feelings properly. What's wrong with him? What should he do? Feeling all alone and restless, he strolls into a gay park and meets... a cat. Youhei is a straight guy, and younger than Kaoru. But something in Kaoru moves his heart, reminding him of a cat, the feline species he's so in love with! Can he capture Kaoru's heart, the abandoned cat?