Taichi Yaegashi

is a member of the Student Cultural Society and the series' main male protagonist. He attends the same homeroom as Iori and Inaba and is a pro-wrestling fanatic. In class, he is a fairly quiet character, always calm and inconspicuous.

Personality
Taichi is generally depicted as a selfless and considerate individual. He will usually go to great lengths trying to help others even if it comes at his own expense or has no direct benefit to him. This trait has earned him the title, "Selfless Freak" by Inaba. He is a fan of pro-wrestling, and has a lot of respect for pro-wrestling jobbers.

Taichi has also proven to be a very patient man; rarely ever getting worked up and always trying to understand the viewpoints of others rather than starting an argument. Of course, he is certainly not above throwing in a few smart remarks, but tries his best not to antagonize people. Taichi is also an honest and hardworking student. He is shown to be one of the more studious StuCS members and he never chooses to copy homework as he finds it to be counterproductive and a bad habit. Taichi is also a doting older brother to his sister, Rina, and, to his frustration, he is often accused of being a siscon/lolicon.

In Yume Random, Taichi states his wish is to "save the world" in the future and chooses to take science courses. "Saving the world" means that he will try to solve problems like energy crisis, malnutrition, and environmental changes.

In Asu Random, Taichi is shown to be afraid of losing his memories of the StuCS and the phenomenons. He obsessively writes the names of his fellow club members in a notebook and reviews past photos to keep his memory fresh. His habit is so serious that even his sister and mother begin to notice something's wrong.

Key Problem
Unable to bear watching other people suffer, Taichi has stated he would rather endure the hardships of others in their place if he could. Taichi's obsession with being selfless is to the point where he has expressed a willingness to throw away his own life just to help another. Inaba has likened the severity of this trait to that of mental insanity.

In Yume Random, Taichi's obsession resurfaces when he chooses to use the power Heartseed gave him to try to help as many people as he can. When Inaba asks him who he is living for, Taichi states he's living for everyone else, disturbing her. Later, his desire to help backfires when he accidentally gives a couple the wrong advice. Taichi soon realizes that his obsession with being selfless has completely consumed his life and has caused him to lose sight of who he is.

Appearance
Taichi is a young man of average height, though noticeably shorter than Aoki. He has short brown hair and eyes, and normally displays a calm face. Aoki suggests that Taichi is quite handsome and he'd be popular if he was more cheerful. Taichi is usually seen in his school uniform.

Background History
Taichi originally wanted to join a "Professional Wrestling Research club"; however it did not have enough members interested in it. As a result, the school placed him in the Student Cultural Society.

Taichi was a part of his middle school's Baseball Club, and as a result, was quite athletically fit. However, according to Yui, by Hito Random he has stopped practicing.

Family

 * Yaegashi Rina: Taichi’s younger sister. The two are shown to be quite close and Rina often pesters Taichi about his love life. Ironically, Rina is usually the one to give relationship advice to Taichi rather than the other way around. In place of their actual father, who is always away for work, Taichi acts as a sort of father figure to Rina, taking care of her, scolding her when necessary, and reminding her to do her chores. Taichi has also proven to be very protective of his sister and initially did not want Rina to meet the rest of the StuCS, though she would later end up thoroughly getting to know each of them regardless.
 * Mother: Taichi's mother takes care of him and Rina alone due to his father working away from home. Taichi's mother is, herself, away during most of the day due to work and relegates most responsibilities, including the caretaking of Rina, to Taichi. Inaba suggests that Taichi's mother is neglectful of her family, but Taichi denies such an accusation. In Asu Random, his mother failed to notice anything strange about him until Rina said something. She initially blamed his strange behaviour on puberty and typical teenager issues.

Friends

 * Nagase Iori: A female classmate of Taichi's and the President of the StuCS club. Admiring her expressiveness, Taichi harbors romantic feelings for Iori and confessed his love to her. Believing that Iori was going to die, they kiss while she was borrowing Inaba’s body. Their relationship never fully develops due to the constant complications brought on by each phenomenon and Iori ultimately rejects his confession after realizing their love was too premature. The two remain close friends and Iori constantly teases Taichi about his awkwardness with romance.
 * Inaba Himeko: A female classmate and the Vice President of the StuCS club. Taichi helps Inaba overcome her insecurities by revealing one of his deepest secrets to her. Over the course of the series, Taichi and Inaba develop a strong bond of trust and need for one another: Taichi helping Inaba with her self-esteem and Inaba helping keep Taichi's "Selfless Freak" tendencies in check. After the class trip, Inaba reveals to Taichi that she has fallen in love with him, but he turns her down as he is still in love with Iori. Despite the rejection, Inaba refuses to give up on Taichi and at the end of the Michi Random arc, Taichi and Inaba begin dating. Inaba, even while dating Taichi, is quite violent towards him, frequently hitting Taichi anytime he says something stupid or makes a smart remark. After Taichi's confession and subsequently getting back together after their breakup in Yume Random, Inaba has largely mellowed out. In Step Time, Iori compares the two to a married couple rather than dating high schoolers. During the opening ceremony of their third year, Taichi finally calls Inaba by her first name, "Himeko."
 * Aoki Yoshifumi: A fellow StuCS club member and Taichi’s best friend. The two often share adult videos with one another and Taichi is the only club member who abstains from teasing Aoki. Though they act as emotional supports for each other, Aoki admits to being jealous of how Taichi is better than him at helping other people, particularly Yui.
 * Kiriyama Yui: A female member of the StuCS club. Taichi helps Yui get on the path towards overcoming her fear of men and the two develop a strong friendship. Yui considers Taichi her most trusted male friend.
 * Fujishima Maiko: Taichi’s class representative. Due to Inaba's intervention, Fujishima considers Taichi a bitter rival in her fight for Iori's affections. Despite their supposed rivalry, Fujishima still cares enough for Taichi to offer friendly advice from time to time.
 * Gotou Ryuuzen: Taichi's homeroom teacher and club advisor for the StuCS. The two are shown to get along well, though Gotou will occassionally take advantage of Taichi's selflessness. Every once in a while, Gotou will share a few words of wisdom with Taichi.
 * Watase Shingo: A male classmate and friend of Taichi. Taichi learns that Watase has a crush on Fujishima. In Asu Random II, Taichi promised Watase that, once they leave the Isolation Dimension, he will help Watase get closer to Fujishima in exchange for trusting Taichi.
 * Enjouji Shino: A female underclassman and fellow member of the StuCS. Shino has a fetish for Taichi's voice and goes crazy when he says even the simplest of phrases. eg. "Do your best" in Nise Random. Shino has expressed a desire to be Taichi's younger sibling just so she can continue hearing his voice for the rest of her life.
 * Uwa Chihiro: Taichi's underclassmen and fellow member of the StuCS. Although initially at odds with each other, further aggravated when Taichi learns what he did to Inaba in Nise Random, Taichi later decides to forgive Chihiro. Chihiro comes to respect Taichi as a reliable figure and frequently goes to him for advice throughout Yume Random. Chihiro continues to feel guilty for the hardships he has put Taichi through, but Taichi insists he does not blame Chihiro.

Others

 * Heartseed: Of all the StuCS members, Heartseed seems to take particular interest in Taichi. In the Yume Random arc, Heartseed personally tells Taichi that the two of them are more similar than he thinks.

Trivia

 * According to Yui, Taichi is bad at smiling.
 * Taichi is a big fan of pro-wrestling, seeing it as the art of enduring physical pain and greatly respects "jobbers": wrestlers who normally throw fights to raise their opponent's popularity.  Moreover, this reflects his personality, as he'd rather endure pain himself rather than see other people suffer.
 * Taichi's favorite food is curry.
 * With the exception of Chihiro and Shino, Taichi refers to everyone by their last names.