It's a miracle that the series isn't softcore porn like its fellow manga in the same magazine (Tsugumomo), considering the author COOL loves just randomly putting sex scenes in his series, and especially his paizuri fetish. He's done it for series that don't have as much/any nudity before up until that point.
You can't really expect tourists to know that though, they haven't read any of his other works.
Yeah its kept at the Ecchi level. But some of his anthology works are different like interspecies reviews darkness.
But series like Ayakashi Triangle are a bit more lewd, lewder the its predecessor and also gets hit with ecchi, which is only level below erotica and 2 below mature.
He likes bewbs (my man), but i saw his second onimai anthology chapter and he does draw different body types. Elmas grandma having two separate human appearances.
For this series it pretty much just nudity in bath scenes which is actually pretty culturally acceptable. People in the west often forget what's considered acceptable by japanese standards. Im in japan right now and a girl said she was surprised how countries like the UK and USA view nudity and s@x.