"Bulge" redirects here. For the dummy character, see Bulge (dummy). For the Uchū Shōnen Bulge oneshot character, see Bulge (oneshot).
Name Astro
Race Human
Birthday August 17 (age 15)
Gender Male
Height 5'01"
Affiliation Industria, Astro's Family
Occupation Prince
Laborer (formerly)
Relatives Chima (adopted sibling)
Sho (adopted sibling)
Macro (adopted sibling)
Okikuna (adopted sibling)
Suntara (adopted sibling)
Little (adopted sibling)
Planetary King of Industria (father)
Black (father figure) (former)
First Appearance
Manga Debut Chapter 1
That Which Pierces

Astro (アストロ, Asutoro) is a young street urchin turned prince and is the main protagonist of Sensei no Bulge series. It is eventually revealed by Black that Astro is the true prince of Industria, Bulge (バルジ, Baruji).

He was originally a poor young man living in the slums of Industria's capital city, but after a fateful encounter with Prince Bulge of Industria, he received his title and status and had since become the new prince of the entire planet.


Astro Full Body

He is a small, pale-skinned, human young man with wild blue hair and a fierce expression befitting his personality. As a commoner he wore simple and tattered clothing which consisted of a blue jumpsuit with yellow buttons, a beige-colored jacket that was torn in some areas, a pair of red work gloves and a red gas mask which he often wore as a hat. As a royal prince he now wears all manner of refined high-class clothing befitting royalty, however he most commonly wears a small gold crown atop his head.


Astro is a courageous young man of great determination and ambition who cares deeply about his friends and adoptive family. Having grown up without a family, he considers having a family to be very important and that families should get along no matter how unlikable one of their members are. He values his adoptive family more than anything and cannot stand to see orphans abandoned on the street and adopts every orphaned child he comes across and raises them as his siblings, doing the best he can to give them the life they deserve. He is also heroic and brave in nature and cannot stand idly by while others get hurt and will often recklessly leap into battle to take down foes. He can also be stubborn or childish at times and does not like taking orders from adults and will make certain mistakes. He also dislikes to show his more sensitive side and tends to hide his tears when around his family.


Becoming the PrinceEdit

Astro was a poor peasant boy living in the slums of Industria's capital, getting by with what little he made from his terrible job to fend for himself and his adopted family. One day, Gordon, an evil alien aristocrat, tried to kill his employer, so he quickly stepped in to save him, however his cruel employer only saw this as Astro putting him on the aristocrat's death list so he fired Astro without a second thought. Gordon however simply through his wallet Astro to avoid any legal issues. Astro returned home that night with bags full of groceries he bought with the wallet but could not bare to tell his kids about losing his job. He then went up to the roof to think when one of his kids Chima tried to cheer him up but then suddenly a mysterious figure appears who reveals himself to be none other than prince Bulge who reveals that he is the spitting image of Astro and wants him to take his place. Astro was both confused and skeptical but Bulge quickly placed the Org, the symbol of his royal status on Astro's wrist, finally giving Bulge his freedom. However just then, Bulge was shot down and killed by his own guards who believed him to be a thief trying to steal from their "prince" who was actually Astro. They then escorted him against his will back to the palace as Chima screamed for him.

After he arrived he was greeted by vice-captain of the military police unit, Tiamat who quickly scolded the "prince" for running away. Astro tried to get out of the situation but feared that he would be accused of killing the prince. He tried to run away but was caught by Tiamat who was less then enthusiastic for having someone like "Bulge" as part of the royal family, this statement angers Astro as he claims that no one has the right to exclude someone from their family, this surprises Tiamat but before he can react an assault is made on the castle by Gordon, the same alien aristocrat from before who recognized Astro and justified his attack on the castle by saying that "Bulge" stole his wallet. Tiamat attempts to fight him off while Astro contemplates whether he should leave amidst the chaos, but can't bare to see the battle go on so he offers himself to Gordon in exchange for the castle's safety, but just then the Org begins to glow, creating a spear of energy in Astro's hand. With this Astro destroys Gordon's beast tank and Tiamat takes care of the rest. Seeing "Bulge" use the power of the Org greatly shocks and amazes the King, Tiamat and the guards, making them contemplate "Bulge's" sudden change.

Powers & AbilitiesEdit

He is rather agile and swift for his age and has a good degree of strength but is currently still an amateur in battle and is undergoing training from Tiamat to improve his skills.


Org: The Org is the sacred treasure of Industria's royal family, which not only symbolizes their status but is also a mystical weapon that only those with the right to rule can wield. Astro is currently the only one capable of using it and it allows him to create a spear of energy that is incredibly powerful and when thrown it moves at great speeds that can pierce through foes with ease and he can also summon it back to his hand after being thrown. Astro later unlocks the ability to change the Org's size and shape; first changing it into a blade, then adjusting the blade's length at will.



He has adopted many orphaned children from the slums that are of both human and alien origin and treats them as his siblings. He cares deeply for them and does his best to give them the life they deserve. He worries deeply for them and now fights to improve Industria and make it a better world for them and all other families on the planet.


Tiamat and Astro have very opposite natures and the two tend to argue and not get along, however both have recently acquired a little respect for one another and he has agreed to train Astro in the art of battle.


  • "No you idiots, this is wrong, let go of me! I'm not the pr-!"
  • "Calm down!! The prince is me, and for some reason the prince got blown away, so if you think of who the culprit could be, then normally you'd think... IF THEY FOUND OUT THEY'RE GONNA KILL ME!!! WHATSHOULDIDO? WHATSHOULDIDO? WHATCANIDO? WHATCANIDO? WHATDOINEEDTODO? WHATDOIDO? WHAT...? I GOTTA GET BACK!"
  • "Right off the bat, things are getting out of hand!"
  • "This... is "meat"...! *Drool*"
  • "I'm the prince scumbag!! I'm gonna pierce straight through you!!!"


  • The origins of how he became prince slightly resemble the events of the novel The Prince and the Pauper.