Raiha Uesugi

Raiha Uesugi (らいは) is the younger sister of Fuutarou Uesugi. She is the one who cooks for the family, and despite still being in elementary school, she's wise beyond her years.

Appearance
Raiha is a slim young girl who stands at a medium height with long black hair, green/brown eyes (in Season 1, brown in Season 2), a simple butterfly-shaped ribbon, holding up her hair in a high cowlick.

Personality
Raiha is a cheerful girl who is essentially the head of the family, despite her young age, since she's the one who takes care of financial matters and cooks for the family. Her mother's absence forces her to spent more time at household matters, leaving her to hold back a lot of things a child normally do. She cares a lot about her brother and concerned about his life, even when both of them have grown up significantly.

History
Fuutarou says that Raiha has been holding back all this time due to their family situation.

Ability
Raiha is good at cooking as she is able to cook various meals. In chapter 23, it is revealed that Raiha has a mediocre, if not poor, constitution, Raiha is the one who cooks in the family.

Raiha is seen to have good wisdom and perception. She has a good understanding of her family issues and uses those circumstances for her/their benefit. Raiha is also hinted to have a shrewd mind, capable of using her expressions to convince people to follow her lead, or exploit her cuteness to achieve her goals, as shown in several occasions. Raiha uses her charms to entice Itsuki Nakano. Raiha is able to connect the four Nakano Quintuplets with Itsuki, despite their different hair lengths and accessories, something that Fuutarou is unable to do.

Isanari Uesugi
Raiha is close to her father and often acts as the straight man for her father's antics.

Fuutarou Uesugi
Raiha knows Fuutarou like the back of her hand. She understands his strength and weakness, while able to control him to a certain degree. She is greatly concerned about her brother's well-being, even made him a good luck charm despite her deteriorating health. She even still worried about the adult Fuutarou and his love life.

One of Fuutarou's motivation and goals in life is to fulfill all of her wishes.

Itsuki Nakano
Itsuki adores Raiha, and have a close relationship with one another since they would even hang out with one another. Itsuki is the 1st quint to meet Raiha.

Yotsuba Nakano
Yotsuba took a liking towards Raiha and indulge her in various Summer Festivals gifts and toys, creating a good relationship between them. Yotsuba is the 2nd quint to meet Raiha.

Quotes

 * "My brother is trash. and egoistical. and like the worst guy ever. but he has a lot of good qualities too!" - Raiha Uesugi (S01E01).
 * "I'll treasure it for the rest of my life" - Raiha Uesugi (S01E04)

Trivia

 * Raiha believes in charms as she is seen making one herself (See Raiha's Charm).