『Fangtasia』's manga / #Dense As A Brick(1)

Concierge No Koibito

Complete | takagi ryou, Takagi Ryo | 2013 released

This isn't a oneshot. There's a full volume. Chapters: 1. Concierge no Koibito 2. Wakadanna no Koibito 3. Shachou no Koibito 4. Bishokuka no Koibito 5. Shodouka no Koibito. I've only read the first chapter available.