I'm looking for a manga I read about a man who time travels by getting drunk. I remember at the beginning, he visited a grave, got drunk and ended up back in high school. In high school, he tried to prevent his dad from leaving the family, but he failed. He also got drunk with his best friend in high school and let slip he was a time traveler. When he goes back to the future, he thinks it was a weird dream. Then, he gets sent a book from his best friend who is now an author with an autograph inside that says, "To the time traveler." So, the man knows his time traveling wasn't a drunk dream after that.

It's an older manga. I remember the author made another manga that was a collection of one shots about trees.

I remember after I read the manga, I went to see if it was here and I couldn't find it. I regret not adding it then.

That's all I remember.

Harukana Machi-e by Taniguchi Jiro

Yesss! That's it! Thanks much, Blake77!