This story is from Comic OEX 2010-02, and it also happens to be ch.5 of Kuroiwa’s latest tankoubon Milky Way. MamaSupe! 2 is still being worked on…
A note on the story: It’s possible that Mutsuko is Hatsumi’s aunt (which would make Hatsumi boys’ cousin) or it could be that they’re just good friends (in either case “oba-san” would be appropriate way to address Mutsuko). Same story with the boys calling Hatsumi “onee-chan”.
Download:
Mediafire
Torrent (updated, thanks Marte!)
In light of certain recent events I got a sudden urge to translate something particularly Harmful To Healthy Development Of Youth. Stay tuned…