I wonder if there is something like that? And without harem... I doubt this is a popular genre for translated novel, but reading "Dating a Team Magma Grunt" made me want to search for something like this.
It's hard to find one with real shota, as most novel/fiction only used shota as growing phase, then they grow up. First volume of Gong Hua. The MC is a shota, although people tend to think he's a girl because he has long hair. And magma grunt is good. I hope the author could continue it.