I forgot the title of novel or manga about a boy that reincarnated as a third prince in a small kingdom. He have a happy family with 2 big brothers and 2 sisters, all siblings is a bro-con to him. His mana is big and he can read magic word (kanji). Then he tamed a legendary black monster, named kuro. Also a fluffy monster like a cat. Then he also made a contract with a female spirit without his knowledge. His common sense a bit off. He can also talk to the tamed monster normally, where there's nobody can. Sorry my English is not too good. Please help me. I even search my bookmarks but I didn't find it... Thank you for your help