|Likes||Jojo's Bizarre Adventure|
|Relatives||Mana Natsukawa (younger sister)|
|Japanese Voice Actress/Actor|
Masuzu Natsukawa (夏川 真涼 Natsukawa Masuzu) is a first year high school student who just recently returned to Japan after spending nine years overseas. She is popular at school, and she is constantly confessed to by the males at school, which made the girls at school jealous. She, like Eita, hates romance and love, and claimed that she hates Eita all along, since he wasn't charmed by her looks.
Masuzu has long, straight, silver hair that reaches her waist, bangs, locks of hair covering her ears, and blue eyes. She also has fair skin. Despite the fact that she looks slim in her school uniform, she is actually very well-endowed, and has a curvaceous figure, as shown whenever she wears her swimsuit.
Masuzu is constantly confessed to by the male students in her school, but she always turns them down. At the start of the series, she was confessed to by the males 58 times in 2 months.
She hates romance. She can be evil and mischievous outside of the school. She is cunning and manipulative, due to the fact that she forced Eita to be her "boyfriend", and even threatened to leak his diary secrets onto the Internet.
She likes to quote scenes from the manga JoJo's Bizarre Adventure. But deep in her heart, she is good. Her twisted personality is caused by her family problems, which also caused her to hate anything about 'love'.
She spent nine years overseas. Her family was situated in Sweden, and she also has a complicated relationship with her father, which particularly causes her twisted personality.
She was known as the jewel of the Natsukawa family, and she was used as a tool and accessory by her father, in order to show off to his high society after taking her away from her mother. She's always been waiting her mother to come back.
Masuzu blackmailed Eita so that she can be his "girlfriend", in order to make the boys from the school stop confessing to her. When she isn't with Eita, she is bold and cold; but when she is, she acts more evil and very devious, and she loves to use words to trick and seduce him. One of her antics is reading Eita's notebook of fantasy that is filled with embarrassing things out loud in front of him, often with Chiwa and/or Himeka around, causing Eita to squirm in embarrassment. Although she just used Eita to form a faux relationship in the beginning, she eventually grew genuine feelings for him without actually realizing it.
In the end of Volume 6 of the light novel, after a tremendous fight with Himeka who accused Masuzu of falling for Eita, the book ends with Masuzu severing the ties with Eita, freeing him from the contract.
At one point, Masuzu broke up with Eita and tried to pair him with Chiwa. However, Eita later found out and confronted her, declaring that she is the one he truly loved, causing them to get back together again.
Masuz and Chiwa were love rivals, always fighting for Eita's love. In the last episode of the anime, Harusaki steals a kiss from Eita which Masuzu sees, and then the episode ends with them having a stare-down.
When Himeka gave the club "Z"-like kanji accessories for their cellphones, Masuzu called her "real".
Ai unexpectedly managed to guess the real reason why Masuzu started dating Eita, and asks Masuzu about it, but Masuzu avoids the question by making a joke on the onion she peeled. Eita also heard their conversation.
Masuzu tried to get Saeko, Eita's aunt, to believe that she and Eita were truly a couple. However Saeko was smart enough to see that they were faking the relationship, much to Masuzu's frustration.
Mana is Masuzu's little sister. They're seen not in a good relationship, but Mana deeply loves her bigger sister, and reports her activity to their father. Mana then tells Masuzu's story to Eita, who then realizes that he's in love with Masuzu, and says that he loves her.
- The word "夏" (Natsu) in her surname means summer, and the word "川" (kawa) means river. Combining the two words would make her surname mean "Summer River".
- Masuzu has a habit of going commando (not wearing panties) which she often teases Eita with, by flashing her bottomless tights.
- She suffered a mental breakdown caused by identity crisis as a result of having to put up her false personality to her father for a long time.
- Although she is good looking in her swimsuit, which often causes her to become the center of attention among men, Masuzu actually can’t swim at all, and drowned after a few meters of struggling.
- She often uses her spare time to read Eita’s notebook, so that she can dig up his embarrassing fantasies in order to use them against him, and writes them down whenever she finds out something new about him, but eventually she’s touched by the last entry of Eita’s notebook which states that he will become a doctor and cure Chiwa's injury.
- Masuzu discovered Eita's notebook in a used bookstore in front of a station.
|Eita Kido ⋅ Masuzu Natsukawa ⋅ Chiwa Harusaki ⋅ Ai Fuyuumi ⋅ Himeka Akishino|