I guess this is an example of love in wrong place and wrong TIME, it appears to me that this should be a love story between Akihiko and Eitarou. They both weren't able to forget(their feelings for) each other despite having their own lovers. It feels like Akihoko loved Ren partly because he looked like Eitarou and Eitarou developed his feelings towards her girl cousin because, like he said, she reminds him of Akihiko. I'm a bit sad knowing Akihiko and Ren had a happy ending while Eitarou disappeared and stuck time traveling and the author did not gave us the ending knowing if Eitarou succeeded traveling in the future to meet both Akihiko and Ren.
I guess this is an example of love in wrong place and wrong TIME, it appears to me that this should be a love story between Akihiko and Eitarou. They both weren't able to forget(their feelings for) each other despite having their own lovers. It feels like Akihoko loved Ren partly because he looked like Eitarou and Eitarou developed his feelings towards her girl cousin because, like he said, she reminds him of Akihiko.
I'm a bit sad knowing Akihiko and Ren had a happy ending while Eitarou disappeared and stuck time traveling and the author did not gave us the ending knowing if Eitarou succeeded traveling in the future to meet both Akihiko and Ren.