Tsundere Yakuza To Chippai-Chan summary:

Michi has lived with the belief that "If you want to be loved, start by believing.” Due to her honest and nice personality, she agreed to be the guarantor of her boss when he loaned money.  Unfortunately, her boss ran away and now she has to pay instead of him. At that time, a guy helped her shoulder the debt, but in exchange for him paying, she has to be his pet.