The way they understand each other is too comforting. Hotaru is taking her own pace at love at the same time taking into consideration the other party 's feelings while Hananoi being who he is, a person who gives too much love. Some people sees Hananoi-kun as a bit weird, but to me his character is the one who gives his all when he loves someone to the point that he never bothered thinking what would be best for his love even if he himself takes the damage. His love may be too overwhelming to his past relationships thats why they never worked out (just as how those two girls said when they where out walking) but to Hotaru his way of showing it is not as suffocating as it seems. She truly considers how Hananoi-kun feels with every action she takes and I think its splendid.
A relationship like this is more mature than those in real life tbh hahaha. Its a give and take.
.. No need to explain.