Asian superheroes or characters, speaking in general, have made an impactful presence in comics. It'd be hard to ignore Asian presence in western comics, given that Asia is the world's largest continent and home to a diverse population. Out of all the Asian countries, one country that stands out for its contribution to pop culture is Japan. This is a country that prides itself on its soft power. Power Rangers, Transformers, Pokémon, etc have only contributed to the amalgamation of Japanese and American culture.
So it'd be a surprise that comics books (American in this case) don't give due space to Japanese characters. There are a plethora of Japanese characters in American comics. Without further ado, here are top ten out of those, ranked.
10 COLLEEN WING
Colleen Wing trained to be an ace martial artist with the supervillain organization, the Hand. Colleen quickly mastered the Bushido Code, Katana and other forms of martial arts under the mentorship of Bakuto.
While her training, she was unaware of the criminal nature of the Hand. In the later part of her life, she headed the Chikara Dojo in New York City teaching martial Arts to disenfranchised street kids. Once she learned the true nature of the Hand, she disassociated herself from the organization. In the later years, Colleen got so powerful that she killed Bakuto to save her friend Claire Temple.
9 KARATE KID
Val Armorr is a futuristic Japanese superhero who is well versed in every form of martial known to mankind. He was raised to be Super- Karate by the superhero Sensei Toshiaki. So his education is the best of both. It's no wonder that Val went on to join the Legion of Super-Heroes and to battle against the Sun-Eater. He's one of the strongest Japanese characters on account of his combat skills. It is to be remembered that Karate Kid was born an ordinary human who trained to be a deadly martial artist. Such is his power that he held his own against the Kryptonian Kon-El/ Superboy.
8 SAMURAI
Toshio Eto aka Samurai has served in Superfriends. When he was with the League, he spent the first half of his career fighting Lex Luthor's Legion of Doom. Toshio is a real nerd, for he taught History prior to becoming a JLA member. Toshio was the chosen one, stuck by a light beam by the Gods of New Genesis to defeated the god of Apokolips, Darkseid. Samurai holds the ability to command the winds, he's swift as the wind. His other abilities are pyrokinesis, ace swordsmanship, and invisibility.
7 Dr. LIGHT (HOSHI)
Dr. Light aka Kimyo Hoshi is an astronomer, a member of the Justice League and a single mother of two. So these are three superpowers, to be precise. She was an asset to the Justice League bin the multi-versal Crisis on Infinite Earths. She was summoned to study a cosmic phenomenon during the course of which she accidentally gained superpowers. She became the target of the beam of light hurled towards the Earth by the Anti-monitor. So she's one of those accidental superheroes to gained the ability to control light! Since then she's aided the League, Doom Patrol, and The Outsiders.
6 SUNFIRE
Sunfire aka Shiro Yoshida isn't an ordinary Japanese character for he is a mutant who can convert solar energy into plasma! Most of the Japanese characters in comics are in one way or the other connected to Hibakusha. Sunfire's mother was a victim of the atomic radiation at Nagasaki. Hence Sunfire grew up with deep-seated hatred towards the United States of America. Shiro was practically raised by his uncle Tomo who once took him to the site of Hibakusha. It is here that Shiro gained his superpowers through mutation. His superpowers have mostly to do with energy absorption and radiation and manipulation; making him one of the most powerful comic characters of Japanese ethnicity.
5 REVANCHE
Although Revanche claims she's the Goddess of Mercy, she says Mercy is not her way to go about things. She believes killing is necessary to maintain the balance of nature. Make no mistake about her ruthless nature because she was raised by Hand operatives to be an assassin. Her actual name is Kwannon, and she's famously known as Kwannon the Assasin. She is a mutant, although not born with a high set of abilities, she trained arduously to be a Ninja for the crime master Nyoirin. Her character has taken numerous turns since she first worked for Nyoirin, we are talking to body swaps (her and Matsuo). From here on, she became Revanche and gained telepathic powers in the process.
4 SUNBURST
Sunburst probably has been given the most stereotypical origin that DC could ever have. Takeo Sato got his superpowers by inhaling erupting volcano fumes (Japan has the world's largest active volcanoes). Little did Sato, the bumpkin know that he had superhero capabilities residing in him. Although he went on to become a movie star and did a mega-hit franchise of movies by portraying a superhero called Sunburst. It was while rehearsing that he realized he had the ability to fly.
Sunburst became a coincidental antihero first. His parents were kidnapped by criminals, forcing him to commit crimes. Years later in Crisis on Infinite Earths, he was enlisted to take down Anti-monitor, which he did. But he lost his life in the process.
3 SILVER SAMURAI
You hear the name Wolverine and Silver Samurai together many a time and that's because Silver Samurai was part of Fox's The Wolverine. He's one of the most powerful characters in comics by the sheer nature of his birth. He was born with the ability to charge at almost anything. Silver Samurai is a gigantic silver armor-clad being. He will be best remembered for knocking down Wolverine in the 2013 movie, The Wolverine by chopping off his claws.
2 KATANA
Have you seen her? Katana, the Japanese swordswoman exudes confidence when she wields her Soultaker Sword. She aces at using this relic of a blade in which she stores the essences of those she slays. Hence the name- soul taker. Her actual name is Tatsu Yamashiro, she was forced to travel to Americ in wake of her Husband's death by the Yakuza order. Her combat skills are unparalleled in the whole of DC. She's an expert martial artist.
Ever since her debut in Batman: The Brave and the Bold (1983), she has aided Batman and his extended all-female family, Birds of Prey.
1 RISING SUN
Rising Sun is known as Japan's premiere superhero. He's one of the most intelligent characters in comics. A solar physicist by profession, Rising Sun aka Izumi Yasunari's family lineage are survivors of Hibakusha (Nagasaki). Therefore his greatest contributions are in the fields of cancer research and dismantling bombs. Nerd and powerful, both.
Izumi has aided the most powerful superheroes, such as Superman in thwarting the threat of ancient sorcerers casting spells on Easter Island. He's stronger than Sunburst, in that he completely erased his memories after the two took down crooks together.