This series is like a little time capsule of 2000s LGBT life in Japan, especially the chapters covering the 2006 Tokyo Lesbian & Gay Parade (now called the Tokyo Pride Parade) and the Tokyo International Lesbian &Gay Film Festival (now called Rainbow Reel Tokyo) also held in that year.
As far as them breaking up in the end like that yeah it's a bit sad but also very realistic, break ups happen, but I'm glad they were able to remain friends.