Naisho ne! Pudding

Raised in Mary Ann Orphanage, the always energetic Princess is 12 years old and her nickname is Pudding. She had a mysterious charm that allowed her to open up to anyone. The gentle-looking Mr. and Mrs. Fields offered to adopt her. Filled with hopes for her, Pudding comes to the Field household, but meets a very eccentric family there. Talking raccoon cookies, Jennifer, who looks a lot different than her age, Jimmy, a surprisingly big baby, and so on. At first, Pudding is taken aback, but she is honestly happy to have a family and becomes friends with everyone. However, she is shocked when she hears Mrs. Field carelessly say, "I took in a normal child to cover up the neighbors' accusations." Crying, she runs out of the mansion and tries to return to the orphanage, but...

(source: Shogakukan, translated)