Seishirō Tsugumi

"I am who I am today because of Ojou. I could probably say that I'm happy just being with Ojou."

- Seishirō Tsugumi

is a hitman who was raised and trained by Claude Ringheart of the Bee Hive Gang. Tsugumi is originally introduced as a male student who transfers to Chitoge Kirisaki's class and has orders to protect her from Raku Ichijō, whom he thinks forced Chitoge into having a relationship with him.

Tsugumi, although considered a side character in both the manga and anime, has several chapters and episodes dedicated to the development of her relationship with Raku Ichijō.

Background
Tsugumi was a foundling who was taken in by Claude Ringheart to raise and train as a hitman; as such, she does not know her true parents. When Claude first met her, he mistook her for a boy, and so gave her a very masculine name (which Claude picked out at random from of a book of names) and raised her as such - which led to people mistaking her for a boy at first sight, even to the present day. Although it has been said that Shū Maiko, Ruri Miyamoto, and Kyoko Hihara were the only people other than Chitoge Kirisaki that knew Tsugumi was a girl. Even after ten years, Claude still hasn't realized that Tsugumi is a girl despite wearing the ribbon Chitoge gave her every day.

Tsugumi and Chitoge are childhood friends who she had tried to keep a ten-year old promise of becoming strong to protect Chitoge. Because of this, She went as far as to abandon her own femininity to protect Chitoge, at least until she met Raku. Tsugumi got her last name Tsugumi from Chitoge.

She was brought back to Japan by Claude to investigate Raku's behaviour and eliminate him if She finds out about Raku's fake feelings for Chitoge. However, after Raku treats her nicely and calls her cute, She begins to develop feelings for him, even though she is too stubborn and embarrassed to admit it.

In America, Tsugumi occasionally worked with a hitwoman, Paula McCoy, with whom she had a rivalry with. Her assassin code name was "Black Tiger".

Appearance
Tsugumi is a beautiful fair-skinned girl with chin-length navy-blue hair that has a big light blue-white bow on the left side with a few hair strands hanging over her face, radiant red eyes, a mole under her right eye and she is said to look very masculine. In fact, Tsugumi was mistaken to be a boy by many people when she first enrolled into high school due to her looks and her uniform. Despite this, her breast size is an E and they are actually still growing.

She is usually seen wearing khaki pants and a white shirt with a red tie that has two thin white chevrons that go up to her chest. She wears a blue blazer over it and wears brown shoes. Tsugumi also wears a blue-ribbon on her head that was given to her by Chitoge Kirisaki to make her look more feminine.

Once, she was shown wearing a girl's uniform, which she was forced to wear by Chitoge. She says that she avoids feminine clothes, including skirts and dresses because they are hard to fight in and are embarrassing to wear. However, when Chitoge asks her to wear them occasionally, she can't help but accept. During a visit to the beach, she wears a skimpy red strapless bikini, much to her embarrassment.

Another case has also been revealed, in which she follows Raku Ichijō, on her date with Marika Tachibana, wearing a purple dress, laced with white, with a glowing brown belt around her waist. she is seen wearing violet color shoes with lace socks underneath and a matching headband with a small grow bow on it. She also wore a wig with pigtail braids.

In Chapter 299, when Tsugumi is talking on the phone about Raku and Chitoge's Wedding, she is now seen with wavy waist-length hair that has bangs hanging on the left side and she no longer wears the light blue-white bow.

Personality
Tsugumi is exhibited as masculine and aggressive. As a sworn member of the Beehive Gangsters, Tsugumi is very loyal towards the organization, especially to Chitoge Kirisaki, as with all its members. Tsugumi is mostly portrayed as serious, focused and somewhat mild-mannered. However, after befriending Raku Ichijō and co., Tsugumi reveals a more feminine and emotional side. Furthermore, Tsugumi is a shy individual and becomes greatly flustered and embarrassed as shown when her mistress would resort her to wear more feminine clothing or when confronted by praise or compliments (especially Raku's). Tsugumi is also rather frank and direct, never hesitating to speak her mind. Tsugumi can also be playful and cheerful at times, proving that she can be sociable.

Tsugumi is dumbfounded by the concept of love, which is shown when she is oblivious of what a love letter is and has no knowledge towards the celebration of Valentine's Day. On the contrary, Tsugumi is quite knowledgeable in how to confront her emotions and how to act accordingly with it which was evidenced when Raku would usually come to Tsugumi for "love advice".

Despite Tsugumi's masculinity, she is usually the target of being groped by her female friends due to her buxom physique, leading Tsugumi to develop a breast complex.

Relationships
"Main Article: Seishirō Tsugumi Relationships"

Abilities

 * Immense strength: Tsugumi is able to crack walls by banging her head on it and able to destroy a portion of a wall with a single kick. When she is extremely angry, she can break a cement pillar with a single kick.
 * Agility: Tsugumi is very agile, able to keep up with Honda and her chain despite the latter supposedly emphasizes speed in fighting.
 * Infiltration and assassination skills: Tsugumi is one of the best hitman of Beehive gang specializing in infiltration.
 * Skill with guns: Tsugumi is shown to be capable of reassembling a disassembled gun and firing it with remarkable speed - even when blindfolded.
 * Skill in cooking: Tsugumi is shown to be very good in cooking and was also remarked by Raku Ichijō.
 * Skill in hacking: Tsugumi can hack school database effortlessly.

Etymology

 * The name Seishirō means "sincerity" (誠) (sei), "samurai, warrior, gentlemen" (士) (shi) and "son" (郎) (rō).
 * It was said that Claude Ringheart was the one who gave the name Seishirō to her.
 * Claude doesn't know that Tsugumi is a girl until the last chapters.
 * For reason above, Claude is the only one who calls her with this name.
 * Seishirō's surname Tsugumi means "thrush" (鶫).
 * The surname Tsugumi was from Chitoge Kirisaki.

Trivia

 * Like Paula McCoy, Tsugumi is scared of ghost stories/scary things.
 * Initially, during her introduction, Tsugumi was shown extremely manly with no visible breasts. However, once her assigned gender was out to the audience, she was given the largest breasts much bigger than any girl in the series as a sign of her feminine interior.
 * In Chapter 68, Raku Ichijō told Tsugumi that she was the first person who gave him chocolates (although it was just obligatory chocolates).
 * As the story progresses, Tsugumi began to show her feminine side more than her masculine side. In the epilogue, she became a model and wore a very feminine dress, suggesting that she already embraced her feminine side completely.
 * Tsugumi has a gun hidden in her right sleeve.
 * In the manga, the gun that Tsugumi has hidden in her sleeve is a Beretta M92.
 * In the anime, it's an S & W M66.
 * In Rival, during the duel Tsugumi had with Raku Ichijō, she used an RPG-7, M249, Remington M870 and several other large firearms.
 * During the duel with Claude Ringheart, Tsugumi hid a weighted chain on her left sleeve, a weapon she studied from her duels with Honda.
 * Tsugumi's situation is very much similar to that of Honda.
 * Both have a female master and call her "Ojou".
 * Both share special moment around their names with their masters (Tsugumi's name was given by Chitoge Kirisaki and Honda's real name is only told to Marika Tachibana).
 * Both are top hitmen with equal abilities.
 * Both are actually given hidden agenda to observe their master by their actual employer (Claude for Chitoge and Chika Tachibana for Marika).
 * Both betrayed their employers and sided with their masters instead.
 * Nearing the end of series, Tsugumi has adapted Honda's signature weapon (a weighted chain).
 * Both have similarly curvaceous figures.