Kou Kou Kyoushi (1993)

Older male character involved with a younger female that is a student. Dark subject matter. And both provide social commentary on what adolescent girls may face in modern Japanese society.

-Both about student-teacher relationship.
-Both they are set in all-girls school.
-Both has dark events
-Both main students are sees as werid

Following a failed confession to her first love, female high school student Mikoto Ochiai contemplates jumping off the roof of the school building. However, her thoughts are interrupted by the arrival of Jin Haiba, the physics teacher known for being a slacker and the butt of students' jokes. Calmly, he lights a cigarette and asks for an explanation of the events that led her to this precipice. Rather than dissuade her from killing herself, he makes a request—will she enter into a romance with him before she dies? Together, the two gradually ponder why they should keep living and why they should not love each other in earnest.

'Aishiteiru to ittekure' is one of my favorite j-drama of all time!!
The story, the characters and even the actors were so much better, But I got really similar vibes from these shows -
The similarity was mainly with the lead couple's age gap, their overall chemistry, the 'teacher's student' trope and the setting of the story.
I feel like if you have seen one of these series, Chances are you will also like the other series.

Both are teacher-student romances with a gloomy, somber tone, complex, well-written characters, and strong performances.

The plot is the same - a forbidden love between a teacher and student.

Both are about a forbidden love between a teacher and student...

Both are about a forbidden love between a teacher and student.....