It's 伴侶の心得 (Hanryo no kokoroe) by
真先 ゆみ (Yumi Masaki). Sadly, the author is not popular, so I don't think you would find even Chinese version online. Well, you can buy Japanese version at online shops, but I don't think you know Japanese, so... But the cover is nice, I have to admit!!
I couldn't even find a page for her in mangaupdates. :(
What manga is this?
http://www.mangago.me/read-manga/koisuru_cupid/mf/v01/c006/