Talk:Light Novel Volume 3/@comment-5645574-20171001151217

Haru (adult haru) in vol. 2 time travel back to haru in vol.1(teen haru) and fuse together again (after in vol. 2 he fuse with his phantom-self) as a result haru become teen form again (forever 17)

he travelling back to change the timeline to saving his friends and his world for being destroyed in vol.2  

haru harem status: increased in vol.3

this is spoiler I got so far for now (copy paste from FB)