Hajime Tenga is a tall, muscular young man with a striking and unconventional appearance. He has spiky pink hair, hazel eyes, and slightly tanned skin. A distinctive lightning bolt-shaped mark on his hairline possibly a scar adds to his rugged look. His eyes have a defined, gentle downward tilt, giving him a surprisingly approachable expression despite his intimidating physique. He also wears lime green bottom-rimmed eyeglasses, a unique accessory that complements his bold appearance.

In his school uniform, Tenga stands out prominently by replacing the standard white collared shirt with a bright yellow t-shirt featuring a black bear logo on the chest. He further breaks uniform conventions by wearing shiny red and white dress shoes, which enhance his rebellious image.

Tenga’s casual style is loud, expressive, and highly individualistic. He often wears tank tops or muscle revealing shirts to show off his build, frequently paired with bold patterns, vivid colors, and flip-flops during summer. His outfits reflect a carefree approach to fashion—he prioritizes comfort over conformity, wearing whatever suits his taste without regard for trends or expectations.

His signature accessory is a white beaded bracelet, featuring two pale yellow beads flanking a larger blue bead at the center.

Standing at approximately 185 cm (about 6 feet), Tenga is noticeably taller than most other characters in the series. Although his appearance and reputation can come off as intimidating, he is described by Katsuhira Agata in the novel as a “handsome young man,” hinting at the contrast between his outer image and inner personality.

Hajime Tenga represents the archetype of the “Musclehead Thug,” one of the so-called Seven Deadly Sins of Modern-Day Japan in Kiznaiver. While he is commonly perceived by others as a brash, intimidating delinquent with a short fuse, this image conceals a deep-rooted desire to help and protect those around him. Beneath his rough exterior lies a genuine concern for others and a surprising level of emotional insight.

Tenga is highly energetic, impulsive, and physically strong, often charging headfirst into situations without much forethought. His spontaneous actions, though occasionally reckless, frequently help to keep the group moving forward during times of indecision or stagnation. True to his role as the group’s so-called “muscle,” Tenga often relies on gut instinct and physicality to confront challenges.

Despite his reputation, Tenga exhibits notable practical intelligence and strong observational skills. He is often able to quickly identify the underlying issues in emotionally complex situations, showing a kind of intuitive understanding that surpasses expectations. He demonstrates this insight on several occasions, often offering blunt but surprisingly accurate assessments of the group’s emotional dynamics.

While his core personality is thoughtful and loyal, Tenga is not immune to emotional instability. When overwhelmed by negative feelings such as jealousy, he can become selfish and even violent, losing sight of his usual good intentions. However, these episodes are rare and typically followed by self-reflection, as Tenga comes to realize the harm caused by his actions.

Tenga also displays a perverse and immature sense of humor, most notably during a scene in which he attempts to grope Nico Niiyama while she explains the “Sleep Fairy” concept, which results in a slap that is felt by the entire group through the Kizna System. He has also made inappropriate jokes about Noriko Sonozaki, referring to “violating” her whenever she provoked him comments that, while framed humorously in context, underscore his tendency to express frustration in crude and exaggerated ways.

Despite his flaws, Tenga’s journey in Kiznaiver reflects a struggle to balance raw emotion with responsibility, and his development shows a shift from impulsiveness toward a deeper understanding of connection, pain, and accountability.

Intelligence and Reasoning
Despite his outward appearance and reputation as a delinquent, Tenga possesses a sharp and intuitive mind, particularly in emotionally charged situations. He has displayed deductive reasoning skills and strong observational ability on multiple occasions. One early example is when he correctly theorizes that the numbers and letters appearing on their wrists during shared pain experiences represent each individual Kiznaiver, helping to identify the source of pain.

Another notable moment of insight occurs when Maki Honoka begins displaying cold and hostile behavior. While the rest of the group is confused by her emotional detachment, Tenga correctly deduces that Maki is suffering from heartbreak, showing that he is attuned to emotional cues even if he struggles to articulate them formally. His ability to cut through surface-level distractions and pinpoint the heart of an issue is a recurring trait that makes him surprisingly effective in both conflict resolution and group dynamics, despite his brash and physical nature.

Physical Strength
Hajime Tenga possesses remarkable physical strength, frequently showcased throughout Kiznaiver. He is capable of effortlessly overpowering opponents, as demonstrated when he sends a group of bullies flying with a single punch while defending Katsuhira Agata. Tenga is fully aware of his physical power and does not hold back in combat, often using his entire body, including his glutes and chest, during fights. He displays a certain enthusiasm for brawling, taking enjoyment in fighting and punching, whether it’s out of defense, frustration, or sheer instinct. His aggressive combat style reinforces his role as the group’s physical powerhouse.

Katsuhira Agata
Tenga first meets Katsuhira in the opening episode when he intervenes in a bullying incident, protecting him in exchange for a portion of his money. Following the formation of the Kizna System, Tenga moves into Katsuhira’s apartment, claiming it would help him better protect Katsuhira since their bodies are now connected. This initial act of care sparks a brotherly bond between them, though their relationship later becomes more complicated.

When Tenga realizes Chidori Takashiro still has feelings for Katsuhira, he shifts his attention from friendship to matchmaking urging Katsuhira to pursue Chidori romantically. However, Katsuhira’s emotional indifference frustrates Tenga, especially when it visibly hurts Chidori. In a heated moment, Tenga physically attacks Katsuhira, expressing deep jealousy and confusion over why Chidori loves Katsuhira instead of him. Though he initially distances himself afterward, Tenga later comes to terms with his own actions, expressing regret and reaffirming his care for Katsuhira. By the end of the series, he admits he can’t abandon Katsuhira, recognizing their bond despite past conflicts.

Chidori Takashiro
Tenga’s interest in Chidori develops gradually after observing her closely. Upon realizing her feelings for Katsuhira, he offers to help her win Katsuhira’s heart, acting as a supportive friend and wingman. However, it becomes clear that Tenga is also developing feelings for Chidori, which he initially suppresses out of respect for her emotions.

After Katsuhira breaks Chidori’s heart, Tenga becomes both angry and emotionally conflicted, eventually revealing his romantic frustration through the Kizna connection. Once the Kizna System is deactivated, Tenga directly confronts Chidori to request clarity and closure, expressing a desire to free her from unreciprocated affection rather than burden her with his. Though she rebuffs him emotionally, they part on relatively understanding terms.

In the final episode, Chidori tells Tenga that she’s been thinking about him a lot lately, though her true feelings remain ambiguous. Tenga, trying to stay composed, breaks into a joyful smile suggesting he holds onto hope while respecting her emotional space.

Tsuguhito Yuta
Tenga initially tries to befriend Yuta, but is brushed off. After learning about Yuta’s past appearance and insecurities, Tenga frequently jokes about it, calling him “fatso” and encouraging him to “show his fatty potential,” much to Yuta’s embarrassment. Though Tenga’s teasing may stem from being rejected, he also shows signs of genuine concern, urging Yuta to eat properly during training camp.

Despite their rocky start, the two reach a level of mutual understanding, and Tenga appears to respect Yuta’s logic and reasoning by the end of the series, even if he continues to tease him occasionally.

Honoka Maki
Although not deeply connected, Tenga is the first to accurately deduce that Honoka’s cold demeanor is the result of emotional trauma specifically heartbreak. He recognizes that her participation in the group stems from a desire to escape isolation, and he defends her fiercely when she’s harassed by a media crew.

While they rarely share personal conversations, Tenga refers to her as a “homie” and holds a quiet respect for her. Honoka, in turn, appears to appreciate his presence and defrosts toward him as the group becomes more emotionally connected.

Nico Niiyama
Tenga views Nico as quirky, cheerful, and slightly chaotic. While he often refers to her as one of the group’s weirdest members, he grows closer to her over time and shows protective, older brother-like behavior, even trying to comfort her when she’s emotionally distressed.

According to the love chart, Nico harbors romantic feelings for Tenga, though he remains completely oblivious until Noriko Sonozaki publicly exposes Nico’s crush. Tenga is shocked and embarrassed, especially when Nico runs away in tears. Though he doesn’t intend to return her feelings, he is persuaded by Yuta to seek her out and properly acknowledge her emotions, mirroring the advice he gave Katsuhira.