The Invisible Man and His Soon-to-Be Wife manga volume 5 features story and art by Iwatobineko.

Tounome and Yakou are finally moving in together! Tounome, the dapper private eye and invisible man, is ever the proper gentleman, and so first arranges to meet the parents. While the quirks of their soon-to-be in-laws prove to be a challenge, the affectionate couple might find some surprisingly softer sides to them beneath the surface… But the latest request to grace the detective agency's doors sparks a burning debate: Have they uncovered evidence of an affair?!