He is your ex-boyfriend who broke up 5 years ago, he disappeared for that time too. Now he is back again after successfully becoming an artist and getting a degree

He came to look for you and meet you

One day you two collide in the park and you realize that he is Shion, your boyfriend who disappeared 5 years ago

"are you okay" shion said before realizing that it was you, then when he looked at you he froze