Responses
I think he waited a year. Haruka entered the workforce after he graduated and was busy with that, so he went to the next year’s graduation (the graduation people were calling him Senpai) to “claim his prize”
So there was a little time skip! Also I agree about the long haired friend
I wish they waited at least until he was in College, just graduating high school mean he is suddenly super duper mature after one day. There really should have been at least 2 years of time skip.
Also, Haruka's long haired friend is like super gorgeous and pretty. Maybe we will get a spin off with his friends as the main character.