Looks like the code for Chocolate Cosmos is:

MYNU TAKU EXPO 2016

Someone posted this on the Discord chat.

Thank you! I was just about to ask about it. I tried for Chocolate Cosmos when she came out and didn't get her so I'm really happy now

Great! Thanks a lot!
That's the kind of gift Nutaku should give in Kanpani Girl from time to time, instead of useless 3*.

Thanks a lot. It worked

Thanks a lot! im in need of hit and pierce girls, this code nails it

Thank you really much but... I DONT KNOW WHAT TO DO WITH A 6* AND FOUR 5* TO EVOLVE Q.Q

Thank you, worked like a charm.

Thanks so much for posting it. Worked perfectly. ♥

Thx a lot!

Thanks! Finally, along with Star Lily, I can beef up my pierce units.