I really like Shimizu Shota and his music, and somehow his voice(or perhaps his style) is so suited to sing this kind of love song: the sweet-I love you-I'll be with you forever kind, ones that will make any girl fall for the guy who sang it to her. At least this song is, I think I would say yes if someone proposed and sang this song to me. The lyrics are so simple that even someone who knows only a little Japanese(like me) could understand the gist of it. But you don't need elaborate words to express how much you love someone. The message is simple, so you only need to say 'suki' to get it across.
Like alot of songs I've listened to, I relate this to my own relationship... although also like alot of songs, it seems to be describing his feelings..., I could very well imagine him saying the same things to me as in the chorus, and lines like 大丈夫 二人なら乗り越えられるよ, and 愛してるよ 苦しくなるくらい ... But that was in the past, I won't be able to hear him say things like this anymore. I made the choice to leave him, and I'll have to live with it.