He has a younger sister, Ruka Tsukinaga, whom he adores. He puts on a much more "cool" facade when talking to her, but when she's not around, he refers to her as "Ruka-tan". When Madara calls her "Ruka-tan", Leo makes a comment on how it's a secret from her that he calls her that. Leo seems to get along well enough with his parents, who worry about him. His father tries to encourage him to go back to school, but does so too roughly. 
|Character||Leo's Nickname||Nickname for them|
Ruka (Younger Sister)
She is a young girl in middle school. In her home series Ensemble Girls!, Ruka loves writing lyrics, but she has trouble performing herself because she is very shy and has stage fright. She idolizes Suzu Kuromori and strives to emulate her behavior.
Ruka is a petite girl with a small build. Her hair reaches below shoulder length, somewhat wavy near the ends and orange, styled in twintails with center-parted bangs. She has light green eyes that are a lighter shade than her brother's. At school, Ruka wears the Kimisaki 1st Year girl's uniform and wears a pink cardigan along with the uniform during winter. She also wears a black ribbon and a silver necklace with a cross hanging below her collar. She wears red Uwabaki slippers as well.
As she does not appear in Ensemble Stars!, her middle school uniform is unknown. It can be assumed that she regularly wears it, as she does with her Kimisaki Uniform.
Some of her other statistics include:
- Height: 149 cm
- Weight: 39 kg
- Blood type: A
- Three sizes: 73/59/76
- Voice actress: Megumi Han (潘 めぐみ)
- Ruka makes her first appearance in Ensemble Girls!, where she is a first year at Kimisaki Academy.
- Leo's nickname for her is "Ruka-tan".
- In Ensemble Girls!, her class is 1-B and she is a member of the Rock Band Club as their keyboardist and lyricist.
- Her birthday is November 30th, making her a Sagittarius.
- Her favorite color is silver.
- Her hobby is versification.
- She's often late to off-site club activities because Leo always gets stuck in traffic whenever he drives her to places.
- According to Robin Hood, she loves cats.