A gentle and caring girl who has initially closed her heart off to animals after the loss of her beloved pet, Lulu. With some help from Hazuki Fujiwara she slowly overcomes it. She is one of the consistent classmates who talks to the girls.
Nanako is a youthful girl with big, rounded brown eyes and short auburn hair worn in fluffy pigtails at the bottom of her head. Her bangs are thick, with a small part at the center.
Normally she wears a puffy sunflower blouse with a pocket at the center, a dark tea-rose skirt trim with ruffles, pale pink socks, and lavender flats with white soles.
Nanako is a sweet and friendly, talkative girl who usually isn't rude or likely to brush off someone unless she wants to avoid them or they act rudely. She often expresses concern over the girls and can be sensitive at times when reminded of incidents she would rather forget.
Since Hazuki helped her rekindle her love of animals, Nanako has opened up severely. She is very patient and kind towards them and loves to cuddle them.
Nanako always loved animals, and she would help take care of them even as a kindergartener. Then one year her parents got her a puppy, Lulu, for her birthday. She was very responsible and tended to her needs, taking her for daily walks through rain or snow, but one day while playing with Lulu, she accidentally threw a stick that landed on the street. Lulu went to get it and she wasn't able to stop her in time. Since then Nanako gave up on animals and pretended to hate them in hopes of moving on. Her parents offered countless times to get her a new dog, but she always refused.
Hearing this sad story, Hazuki came up with a plan and lied to Nanako after she refused to show up and help with their class rabbits. Hazuki confronted her and claimed that it was her turn to look after Lulu, one of the bunnies but because she was too busy to do it, she needed her to take over. Nanako tried hard to refuse, but Hazuki forced her. Initially, she was unhappy and often complained, but not too long after she began to bond with the rabbit. But when she left the room to get something for it, she hadn't been aware of the opened window in her bedroom, allowing the rabbit to escape.
Calling the girls, Nanako met up with them and they attempted to find Lulu. They managed to locate her, having been attacked by the Mean Cat, who they forced away and tried to get help, which is when their teacher showed up to lend them a hand, taking them to the pet hospital. Nanako angrily told off Hazuki for what she did, but she eventually apologized after Lulu got better, and came to visit her while she was recovering from her sudden illness.
Okada - Oka means ridge and/or hill, Da means rice field.
Nanako - Nana means vegetables and Ko means child.
- In the first episode, Nanako was originally depicted wearing a darker colored top and had dark purple hair. But before the scene ended, they returned to normal.