Tokiko Tsukuyomi

月讀時子 月読 時子（つくよみ ときこ）

Tsukasa's guarantor. One of the witnesses for Nasa and Tsukasa's marriage registration, 81 years old at the time. Lives in a prime location at "1-28 Toranomon, Minato Ward." Built wealth as a single woman, a former Minister of Education, Culture, Sports, Science, and Technology. Known as a wealthy person, entrepreneur, former politician, and scientist. Married an American and had a daughter named Shiori, but her husband passed away early. A whimsical personality, when meeting Nasa for the first time, she hid her relationship with Tsukasa while testing Nasa’s character and his love for Tsukasa. She also teased Tsukasa by talking about her personality to Nasa. Orphaned by war, she was taken in by Tsukasa and given the name Tokiko. Among living people, she understood Tsukasa best and described Tsukasa's human traits as "hopeless," while continuing to call her "big sister" when no one else was around. For Tsukasa's sake, she was involved as a computer technician in the Apollo program, which sent humans to the moon. The moonstone that was in the room where Tsukasa lived before marrying Nasa was also obtained by Tokiko for Tsukasa. Later, as a "wedding gift," she gave the moonstone to Nasa. She continued to make remarks entrusting Tsukasa to Nasa. In Chapter 145 of the series, it is revealed she passed away due to illness (date of death July 20th), and according to her will, her ashes were scattered “in December by Tsukasa and Nasa” at a lake with a view of Mount Fuji, near the campsite originally owned by Tokiko.