It's cute, but.... I just think the protagonist of a harem manga should earn their harem, over a few chapters. Not have it thrust upon them, in the first chapter, for no apparent reason. This way seems forced, and uninteresting.
Well to be fair, it's not uncommon for a male harem lead to just have his harem (sometimes literally) just randomly dropped on him
I do wonder if there will really be 100 girls or if it will be those three and 97 nameless background characters.