Bleach is one of the greatest and one of the most iconic Shonen anime ever created. Originally written by Japanese manga illustrator Tite Kubo, the manga ran from 2001 to 2016, with the series inspiring an animated TV show, four animated films, several video games and most recently a live-action adaptation that is set to be released in the next few months.
The animated series was canceled prematurely in 2012 and the manga ended in September 2016, however, one thing has been and still is on the minds of many Bleach fans, why I Ichigo's Zampakuto not heavy? I mean the thing is huge, how does he not struggle to wield it around.
In an interview some years ago, Bleach creator Tite Kubo revealed exactly how Ichigo can move around so freely with such an enormous weapon.
"To begin with, a zanpakutou isn't something you'd swing with your muscles. Ichigo's zanpakutou comes from inside him, so he wouldn't find it heavy. If Ichigo tried to wield Renji's zanpakutou, Zabimaru, he'd find it heavy," said Kubo.
"Zabimaru looks pretty heavy, too. Ichigo wouldn't be able to wield him. Renji would probably find the same thing with Ichigo's zanpakutou, Zangetsu," continued Kubo.
So there you have it, that is why Bleach fans favorite hero can throw around an enormous sword so easily. Ichigo's Zanpakutou is apart of him, like an extension of his arm that is attached to his soul, that is why Ichigo can wield such a large weapon.
You can read Viz Media's synopsis of Bleach below:
"Ichigo Kurosaki never asked for the ability to see ghosts—he was born with the gift. When his family is attacked by a Hollow—a malevolent lost soul—Ichigo becomes a Soul Reaper, dedicating his life to protecting the innocent and helping the tortured spirits themselves find peace."