Tsukasa Yuzaki, née Tsukuyomi

The heroine of the story. Height: 154.0 cm (petite). Born on April 3rd, she claims to be 16 years old. Her blood type is O, and her zodiac sign is Aries. She has always cherished a deerskin barrette given to her by a benefactor (a gift from the emperor 1400 years ago as a token of gratitude for advice, though Tsukasa is unaware that the benefactor was the emperor).

She saves Nasa from a traffic accident by putting herself in harm's way but then disappears. However, in accordance with the promise to "marry" Nasa, she suddenly reappears in front of him about two years later, and they get married and become a couple. Her maiden name is "Tsukuyomi," and she becomes Yuzaki after marrying Nasa.

According to Nasa, she is "the cutest bride in the universe," and when this statement was revealed to his parents, she was bewildered and embarrassed. Initially, Nasa calls her "Tsukasa-san," but when deciding on how to address each other as a couple, it changes to "Tsukasa-chan."

When asked why she decided to marry Nasa, who confessed to her immediately after they met, she tells him, "Because you believed in me, I decided to believe in you too." As she gets to know Nasa more, she likes that he "can care about others more than himself," "cherishes their memories," and "can handle sudden difficulties accurately." She often finds Nasa's sleeping face "cute."

After Nasa's first apartment catches fire and they start living with the Arisugawa family, she begins helping with the Arisugawa family's bathhouse work as a part-time job.

Personality and Behavior

Regarding expressions of love as a couple, she responds to Nasa's requests, albeit shyly. When embarrassed, she often tries to cover it up by acting cool. However, she is quite lonely and jealous, despite trying to appear cool to others. When she learns that Nasa will be a volunteer lecturer at a girls' school, she worries about whether the schoolgirls might seem more attractive than her, even though she doesn't doubt Nasa's love for her. She asks Nasa to prove through his actions that he prefers her over the schoolgirls whenever he meets or talks about them. On the other hand, she also has a clingy personality. When Nasa returns home late from a part-time job, she seeks hugs and kisses from him due to the loneliness of being apart.

Hobbies and Preferences

She has an unexpected side of liking TV, movies, anime, and games, and was greatly shocked to find that Nasa's house didn't have a TV. She is particular about movies, watching everything from blockbuster hits to B-grade films, and plays various games from old to new, showing considerable skill in the games she is dedicated to. She is also competitive and easily provoked. Additionally, she shows interest in low-resilience mattresses and gets excited at service areas late at night, indicating her curiosity.

Strengths and Weaknesses

She confidently states, "I can make anything as long as I have the ingredients," and "I can even make sushi," and is indeed skilled at cooking, able to cook rice in an earthen pot. However, she initially struggled with handling the smartphone Nasa bought her (she didn't have any mobile devices when she came to Nasa) and mistook a remote control with dead batteries for being broken, indicating she is not good with machines (though she can handle them normally once she gets used to them). She falls asleep easily but has a very bad sleeping posture, which she refuses to acknowledge.

She has good athletic ability and stamina, can handle swords, and is skilled in martial arts, having reportedly defeated bears and wolves with her bare hands.

Hidden Mysteries

Her past is depicted as mysterious. She demonstrates feats such as handling a Japanese sword owned by Nasa's father, Enishi, and easily deciphering ancient Japanese documents in Enishi's room. When visiting her home in Nara, she speaks as if she lived during the Heian period and talks as if she met historical figures like Oda Nobunaga, Tokugawa Yoshimune, and Taira no Masakado directly. She is also very knowledgeable about Japanese history. When asked by Tokiko to establish connections overseas, she refers to a post-war U.S. president as "Ike" and speaks with him familiarly over the phone.

Furthermore, she was unharmed after colliding with a truck at the beginning of the story and has stated, "My body... doesn't get sick or injured..." She also tells Chitose, "Since the first time we met... I've always been a normal 16-year-old girl," and despite three years passing since the accident when she met Nasa, her appearance and age have not changed, hinting at "hidden mysteries" from the start, which Nasa has also vaguely noticed.

Immortality

Her true identity is someone who became immortal after being given the elixir of immortality "Hōrai" left by Princess Kaguya to the emperor before returning to the moon, living for about 1400 years in the form of a 16-year-old. The emperor ordered his retainer Iwakasa to dispose of Princess Kaguya's elixir of immortality, but before doing so, Iwakasa gave the elixir to his daughter, who was suffering from an incurable disease (her name at the time is unknown, and she has forgotten it herself), resulting in her recovery and becoming immortal, which is Tsukasa. Tsukasa's blood also has a healing effect on others, and she gave a little of her blood to Nasa, who was severely injured when they first met, to heal him.

The name "Tsukasa" was given to her by Prince Shōtoku, whom she met in the past, with the hope that she would become "one who governs human history." In Volume 16, it is also mentioned that she was asked to join the mission to Sui. She seems to have traveled around the world afterward, having been to America before it was called America in the 16th century and Paris in the 18th century, and appears to be able to speak multiple languages.