Shin Megami Tensei: Devil Summoner (1997)

One day, high-school boy Yamada bumps into the beautiful girl Shiraishi on the stairs (literally), and their lips touch as they fall. When they regain their wits, they realize that they have swapped bodies. As time progresses, the two realize that this is not the only mysterious happening in the school.

Nobunaga was a teacher who was waiting for that kind of dating sim event to happen in real life. One day, a 14 year old girl named Kicho appears in front of him, saying that she's his wife?! Apparently she came from the Warring States era and seems to have mistaken Nobunaga for the Oda Nobunaga and tells him that she wants to have his children. An age-gap love comedy featuring a teacher with a dating sims brain and a princess with a warring states era brain!!

At the end of the second semester of third year of high school, four students are prepared for graduation and feel the ending to their high school life. But that changes a little with the arrival of a transfer student.

Hiyori Iki is a normal middle school student until she was involved in a bus accident while trying to protect a stranger. This incident causes her soul to frequently slip out of her body, and she becomes aware of the existence of two parallel worlds. Through her soul, she meets the strange, nameless god without a shrine, Yato. Yato is determined to make a name for himself out there by accepting any wishes for 5 yen, including Hiyori's to fix her body.

Ichiro Sato is about as average as a student can get... except for his above-average ability to land himself in totally awkward, intensely risqué situations with his no-nonsense teacher, Kana Kojima! Ichiro has his hands full dealing with these steamy shenanigans and unexpected encounters in the most unlikely places. At least it can’t get any worse, right?

Like many hardworking members of the workforce, Kuroto Nakano is perpetually stressed out by his job. Still, since he lives alone, he must carry on to sustain himself. Little do humans like Kuroto know, this stress takes the form of darkness residing within a person's body and will bring one's life to ruin. Fox deities can see this darkness and have the duty to save people before it is too late. To help rid Kuroto of his stress, Senko-san, an eight hundred-year-old foxgirl, volunteers to take care of him, and will do everything she can to ease the tension in his weary soul.

A samurai lord has bartered away his newborn son's organs to forty-eight demons in exchange for dominance on the battlefield. Yet, the abandoned infant survives thanks to a medicine man who equips him with primitive prosthetics—lethal ones with which the wronged son will use to hunt down the multitude of demons to reclaim his body one piece at a time, before confronting his father. On his journeys the young hero encounters an orphan who claims to be the greatest thief in Japan.

Being just a normal student without a special talent, Makoto Naegi wins a lottery to attend the prestigious Hope's Peak Academy where only the top prodigies attend. However, instead of this being the beginning of a wonderful high school life, it's a ticket to despair, because the only way to graduate from Hope's Peak Academy is to kill one of your fellow students or be one of their victims.

Kisaragi Amatsuyu is invited out alone by the cool beauty upperclassman Cosmos and his childhood friend Himawari. Expecting to hear their confessions, he triumphantly goes to meet each of them in turn. But Cosmos and Himawari both instead confess to Amatsuyu that they like his friend. Amatsuyu fights this lonely battle, but there is another girl who is looking at him. She is a gloomy girl with glasses and braids. Amatsuyu finds that he hates her, because she's always turning her sharp tongue only on him and finding enjoyment in his troubles. But it turns out that she's the only one who actually does like him.

As one of the thousands of Japanese students afflicted with "chunibyo," a state where they're so desperate to stand out that they've convinced themselves that they have secret knowledge and hidden powers, Yuta spent most of his middle school years living in a complete fantasy world. He's finally managing to overcome his delusions but his chunibyo have attracted the attentions of another sufferer, and she's decided that this makes him her soul mate.