Sekai de Ichiban Aishiteru

High school student Tsukigi Renya's powerful pheromones make him so popular that he can barely function normally. He's driven to lust by every female on the planet and intimidated by every male. Because of this, he lives a lonely life, unable to make a single friend. But one day, he encounters a strange-looking cat(?). Renya is delighted to meet a creature that isn't driven to lust or intimidating, but the cat(?) turns out to be an extraordinary creature from outside Earth...!

This is the start of a tentacle-based non-human love comedy featuring a transforming creature and a protagonist with troubles with women!

(Source: Kadokawa, translated)