"It has strong sense of justice, and is very athletic", an organiser said.
Mascots, locally known as "yuru-kyara" or "laid-back characters" are popular in Japan.
"These two are very different in design but I think they have quite a unity between them", she said, evoking a theme that resonates well with the Olympic movement.
Taniguchi's design received 109,041 votes, while the two other finalists secured 61,423 and 35,291 votes, respectively.
Names for the mascots have not been revealed, with the Olympic committee saying they will reveal those over the summer. Its superpower is moving things by simply looking at them.
The pot-bellied, red-cheeked bear known as Kumamon - created in 2010 to promote Japan's southern Kumamoto region - raked in $8.8 million a year ago for local businesses selling branded products.
One of the students at Hoyonomori Gakuen School where the selection was announced, Miu Kawa, 12, said she was very excited the "futuristic" designs won.More news: Fortnite Next Update Will Speed Up Building
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Sadly he will not receive any royalties as all intellectual rights will go to the International Olympic and Paralympic committees.
The one-eyed characters were dubbed "bizarre" and "creepy" by some, reportedly sending shares in their manufacturer down by more than a third.
The naming and official launch of the mascots will take place later this summer.
The original official logo was hit with plagiarism allegations and scrapped.
"(These designs) embody tradition, the future, cuteness and sophistication, and I believe that they represent today's Japan perfectly", said Yoshiko Ikoma, deputy head of the Tokyo 2020 Olympics mascot selection panel.
The winning designer, Ryo Taniguchi, is an illustrator from Fukuoka in southern Japan.
The win, ahead of compatriot Shoma Uno, who took silver, made the 23-year-old Hanyu the first man in 66 years to defend an Olympic title.
"I want to tell this to my beloved wife".