Her. The mangaka is a woman:
https://myanimelist.net/people/3703/Miki_Yoshikawa
Your point?
I don't think she is trying to make a point, just pointing out that the mangaka is a woman and not a man, since you refered to the mangaka as a man. ╮(￣▽￣)╭
Point is you claim this author is famous for being "unable to write an ending to save (her) arse", yet obviously don't know anything about this author. She is not the author of TWOGK (that's Wakaki Tamiki). Her actual works include:
* Magazine Heroines on the Beach
* Magazine Ohanami!!
* Yamada-kun to 7-nin no Majo
* Yankee-kun na Yamada-kun to Megane-chan to Majo
* Yankee-kun to Megane-chan
So which of these are you claiming have poor endings?
Ah, yes, the mangaka that is famous for unable to write an ending to save his arse. I would expect ending on the level the World only God knows.