Saburo / Hojo Mutsumi

Saburo from the flash series

623 ariwork


First appearance Keroro Gunso Volume 2 Encounter 19: The 623 Incident!!
Keroro Gunso Episode 1–B
Voiced by Akira Ishida (Japanese)
Joel McDonald (Funimation)
David Lee Mickinney (Animax)
Jaime de Diego (Spain)
Ray Li (Hong Kong)
Wordplay name 623 / 326
Aliases 623 (Anime)
326 (Manga)
Age 16
Gender Male
Species / Type Pekoponian
Occupation Student / Radio Host
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Saburo Mutsumi (睦実 サブロー Mutsumi Saburō ), also known as Hojo Mutsumi (睦実 北城 Mutsumi Hōjō ) in the manga) is a main character in the Keroro Gunso series.

Saburo also goes by the Stage name 623 or 326.

Saburo also appears frequently in Seven of Seven as the radio DJ "623". Mine Yoshizaki, the mangaka of Keroro Gunso, did character draft work on Seven of Seven - Saburo is one of several characters who cameo on the show.


Saburo is a middle school student with an I.Q. of 350 and is Kururu's partner.

Saburo skips class a lot and is rumored at school to be a member of a gang called the "Men in Black", though that doesn't seem to affect Natsumi's high opinion of him. He turns out to be a loyal and gentle, but solitary guy - if he's aware of Natsumi's crush, he hasn't shown it, though he does take pain in reading out her postcards when she sends them in to his radio show.

Saburo is excellent in sports, academics, poetry, art, and philosophy, which is why he has a hard time fitting in with his classmates, and he hosts a late-night radio program which Natsumi compulsively listens to. He is the least-active main character of the series, but plays a fairly significant role as Kururu's partner/friend and Natsumi's crush. In the anime, Saburo's identity as Kururu's collaborator is at first a secret (though it's quite obvious), whereas in the manga it comes almost immediately to light.

Episode 112 of the anime depicts how Saburo and Kururu first met. Since then, because of the fact that they shared the same wavelength, they became occasional partners. Saburo's name comes from Japanese wordplay (Saburo means 326, and Mutsumi means 623). Saburo's wordplay name, 326, also first appears in episode 112 on the Reality Pen. Kururu gives him the Reality Pen, which makes any drawing on a flat surface real.

Saburo in his first appearance in Volume 2, Ch. 19

In the anime, his identity as 623 is only known as the radio host, and his identity is kept secret to the public, while he uses his identity as Saburo in public life. While the 623/Saburo connection is hinted at several times in the anime, it isn't until episode 163 that this is officially revealed.

In the chapter 298, is revealed that sometimes he goes to other dimensions using the pen, but that is a secret that only Fuyuki Hinata knows.

Appearance Edit

Height: 168 cm

Weight: 59 kg

In the anime, Saburo is a fairly tall character with tan skin, royal blue eyes and short, spiky silver hair. He usually wears a white bucket hat pinned with a yellow spiral, representing Kururu's symbol.

In the Flash series, Saburo's skin is a lighter tan and his eyes appear to be a litter shade of blue. He is depicted with small white wings, much like his manga design.


During his introduction in the second volume, Saburo is shown as calm, cool, and mysterious. However, when he reveals Kururu to the platoon, he shifts to a happier personality. He accepts Tamama's ideas about Coke from the faucets with joy, saying that it was a great idea.

Relationships Edit

Keroro Platoon Edit

Saburo is the least participant human who is aligned with the Keroro Platoon, and has made the least appearances. However, this does not mean he is lazy or weak, in fact, quite the contrary. He volunteers on plots that interest him, frequently jokes around with the platoon members and is a very good comrade when in serious battles. In his appearances, he gives a great deal of support with the help of his virtual reality pen, which can create unimaginably powerful weapons and fascinating objects if he puts his imagination into it and draws it on paper, and with a quick and cunning mind Saburo has. This is pretty much the perfect weapon for him. He also maintains good relationships with his comrades, thanks to his easygoing nature and is never seen to be completely enraged or angry.

Kururu Edit

Kururu is the first member of the Keroro platoon that Saburo has met, but their beginning isn't exactly much for a start of a companionship. Kururu and Saburo immediately engage in fight, which after a surprising turn of events, Saburo saves Kururu's life while he gives the boy his virtual reality pen in return (anime). Since they're both misunderstood geniuses, they are capable of getting along with each other, and Saburo seems to be the only one who is shown to care about Kururu as a true friend. Saburo helps Kururu and his comrades on broadcasting-based plots, since Saburo is the anonymous (at least in the anime) 623, a popular radio DJ whom Natsumi is a big fan of. In the episode 229, when Kururu is alone, he says that he "can not let [their] bonds fade" and blows the whole invasion budget just to help Saburo. This hints that Kururu cares about Saburo as a friend as well.


Natsumi Hinata Edit

Natsumi has been hinted to have a crush on Saburo ever since the first episode of the anime, but played no further part in some later episodes but his anonymous (at least in the anime) alter-ego is introduced as Natsumi's favorite radio DJ. Then later, in episode 9, he is introduced as the human partner of Kururu, the most secretive, sly and somewhat irritating member of the Keroro Platoon. Ever since then, Natsumi and Saburo have had more closer encounters before, but almost all of them end up as Natsumi being very embarrassed. Saburo thinks of her as a friend but hasn't showed any other feelings yet, while Natsumi desperately wants to confess to him. Sometimes Saburo acts like he may not notice, and sometimes he knows Natsumi Hinata likes him.

Koyuki Azumaya Edit

Koyuki is one of his close friends, Saburo connects to her and they both support each other, often she connects with him than any other guy, they like to hang out with each other mostly when he is associating with Dororo. Koyuki sees him as a dear friend, who she can trust. In the manga, he gives her nicknames such a cutiepie and ninja girl, he is flirtatious around her but also expresses a caring/friendly emotion when she is present. When there is danger, they work as a team along with the Hinatas, and Momoka, she has strong feelings for him as he does for her, in the Anime they have a similar connection and have a close relationship.

Fuyuki Hinata Edit

Originally, Fuyuki feared Saburo, much like the other students at school and when Natsumi stated he was invited over to their house, Fuyuki feared he knew about Keroro and wanted to capture him and the others. Despite the rough start, the two have become close friends. Saburo causally talks to Fuyuki on a daily basis, even hugging him upon greeting.

Other Appearances Edit

In Seven of SevenEdit


623 in Seven of Seven.

Saburo appears for the first time in episode 6 as the late-night radio host 623. From there onward, 623's voice is usually featured at least once per episode on Nana's radio, and often just before the ending credits as well, toting a poem written by the DJ. Saburo's poems were often seen in the early Keroro stories as well; in the manga, he is a self-titled philosopher with an easygoing nature. 623 met Nana when she came to his radio station, and he appears again in person later in the series.

The most notable difference between the Seven of Seven and Keroro Gunso versions of Saburo is the color of his hair; in the former, it is an electric blue, and in the latter, a silvery-grey. He's voiced by Akira Ishida in both shows, though in Seven of Seven his voice is credited as simply "623, by 623." In the English dub, he is voiced by Sebastian Arcelus.

Etymology Edit

The kanji for Saburo's last name, Mutsumi (睦実), when put together mean Friendly Truth.

Trivia Edit

  • Saburo appears the least out of all the main characters and coincidentally, gets the last line of the series.
  • His first kiss was with Giroro (episode 265-b), which was also Giroro's first kiss


Mutsumi Saburo wallpaper
Click here to view the gallery.

See AlsoEdit

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