No harem, sure, but no cheat either? Are you sure your friend really wanted to read isekai!? Anyway: Isekai Izakaya Nobu Isekai Shokudou Cook of the Mercenary Corps Grimgar of Ashes & Fantasies From Maid to Mother Nihonkoku Shoukan GATE: JSDF Fought Here Kyou Kara Maou! Ore no Ongaeshi: High Spec Murazukuri Rune Troopers Ascendance of a Bookworm Risou no Himo Seikatsu Takarakuji de 40-oku Atattandakedo Isekai ni Ijuu Suru Saving 80,000 Gold in an Another World for Retirement Common Sense of a Duke Daughter Log Horizon
Does he have a reading list or something? more: Seiun wo Kakeru The Bathroom Goddess Isekai Ryouridou Isekai Izakaya Nobu (BarryKaiser didn't mention the full title, so I clarified it ) The Annals of the Flame kingdom Slime Tensei Monogatari (I'm not certain about the no cheat part, but I think he does grow stronger slowly and within the rules of that world) Even a Cicada Becomes a Dragon If Reborn (as a newborn dragon MC is strong, but this story is anything but generic)
That's a great idea. Write something like Invisible Dragon...or maybe make him read Invisible Dragon! Or the other 7 or 9 forbidden novels of NU. Someone once told me about there being something like that.
Okay he definitely has too much time on his hands, says he’s read most of them(Again). My god, I’m starting to think he’s finished the whole isekai genre. It’s probably pointless at this point to recommend anymore so I’d recommend not doing that.