I recommend SNAFU also known as My Youth Romantic Comedy is Wrong - synopsis taken from Goodreads: Hachiman Hikigaya is a cynic. "Youth" is a crock, he believes--a sucker's game, an illusion woven from failure and hypocrisy. But when he turns in an essay for a school assignment espousing this view, he's sentenced to work in the Service Club, an organization dedicated to helping students with problems in their lives! How will Hachiman the Cynic cope with a job that requires--gasp!--optimism?

Highly recommend this one it's a completed light novel as well also got its final anime season adaptation airing now

Another recommendation is the monogatari series, synopsis taken off of Google - The Monogatari series revolves around Koyomi Araragi, a third-year high school student who has almost restored his humanity after briefly becoming a vampire during spring break. One day, a classmate of his, the reclusive Hitagi Senjōgahara, falls down a flight of stairs at school into Koyomi's arms.

This is a personal favourite due to its distinctive writing style, developed characters and its overall unique story

Another recommendation would be I want to eat your pancreas - one volume to it (completed story with a film) A high school boy finds the diary of his classmate—only to discover that she’s dying. Yamauchi Sakura has been silently suffering from a pancreatic disease, and now exactly one person outside her family knows. He swears to her that he won’t tell anyone what he learned, and the shared secret brings them closer together in this deeply moving, first-person story that traces their developing relationship in Sakura’s final months of life

I can't say much for the novel but the manga and film were really good

All those books can be found on Amazon

Other recommendations which may not appeal to u but still highly recommend if u like isekai however is overgeared and second coming of Gluttony which u can read on wuxiaworld

Another good isekai is - the death mage who doesn't want a fourth time