She bears a number of resemblances to Shiori Fujisaki, the main female lead of the first Tokimeki Memorial, and excels at everything she does.
Due to the large load of work she is responsible for, she is very busy and seen carrying a folder all the time.
When the protagonist makes a good relationship with Yu, he knows her weakness, like she always loses her way, and her stories what he hasn't known.
However, when her graduation day comes, she ends up not being courageous enough to confess to the protagonist (who is one year below her), and thus misses the opportunity she has always dreamed of.
Like Shiori, Yu is the hardest character to end with in Tokimeki memorial 4.
To win her heart, player is required to have very high status points in every area, as well as able to gain admission to the first rate university.
She initially hates the protagonist for being friends with Maki and will continue to do so unless the player dates her to a certain point.
Due to these characteristics, Tsugumi is considered the "tsundere" girl of Tokimeki Memorial 4.
Rhythmy's storyline is mainly about her composition based on her high school life.
During school, she spends most of her time taking a nap on the rooftop, chilling out at Kirameki riverside park, or going to game arcade.
Kai's storyline is mainly about her decision to succeed Ryukochi Zaibatsu or to be a normal girl.
Although she has a blond hair and blue eyes, she is a half-blooded Japanese born in Miyagi Prefecture.
If the protagonist can get her to confess her love under the legendary tree at the end, she will be waiting there, wearing Kimino.
She often gives meaningful advice to the protagonist if he joins the chemistry club, as well as tries to take care of him.
This is partly because She is very conscious about the fact that she is an upperclassman, which is reflected in her calling the protagonist "Kouhai" (underclassman) throughout the game.
It is revealed later on that Aki is so interested in making supplemental nutrition because her mother works hard to support the family, so she wants her to stay beautiful and young.
She is also scared easily, so it is not a good idea to bring her to places like haunted mansions.
She helps the protagonist with a lot of things, including waking him up in the morning, bringing him monthly allowance, and giving him information about other girls in Kirameki high school.
The bunny's appearance is a cameo of the reoccurring Silent Hill object known as Robbie the Rabbit, subtly foreshadowing Miyako's hidden nature with a company in-joke.
She is initially not datable, but if the player asks her out for a certain number of times, she will eventually agree to date the protagonist.
Once the player starts dating Miyako, a series of events will lead her to misunderstand that the protagonist does not really care for her.
She no longer tells the protagonist girls' information and stops bringing him monthly allowance.
If the protagonist dates any girl during this period, he will have to fight the evil spirit of the bunny doll.