The Case of Being Loved by a Heartbroken Older Woman Next Door After Saving Her

The protagonist, an ordinary high school sophomore, has a woman on his mind.
She is a woman who lives in the next room in the same apartment building, a beautiful and stylish older woman.

He wants to get close to her somehow, to talk to her more, but she has a boyfriend. So the main character has no choice but to give up.

But one day, he witnesses her attempt to commit suicide.