Wow... this is kinda a messed up relationship and i doubt this is really enough to base a ongoing series off of... but i wish there was a bit more. (Also dang this gives me ideas for a story i have been stalled on for a month or so.)
Yan-san and Dere-san have a great relationship, and it would be a shame if someone messed up and caused a bloodbath.
Don't you mean Yan-san and Yan-san? Because they're both obviously yan for each other, even if Blonde Yan-san ended up becoming the bottom in the last part for some reason when they were always more or less on equal footing.