Actually, Blue was the third version in Japan, which had some fixes compared to the original Red and Green. The international Red and Blue were based on the Japanese Blue. Yellow is a fourth version made after the success of the anime.
Harumi's mother already approved her relationship with Chiaki. lol
Also, she (the mother) is apparently lesbian too. xD
I wish Harumi would tell Chiaki she loves her already.
From the way page 17 was framed and the events leading up to it, I was kinda worried for a minute that they were still naked while they were getting married.