If only sibling rivalry were always this adorable.

They start with a shout and an honorary bow before they take a stance that means business. These kids may still be able to count their age on one hand, but when that hand becomes a fist you’d better watch out!

▼ They may just kill you with their cuteness!

Older sister Hana and younger brother Haru are driving their Twitter followers (all 137,000 of them!) nuts in their latest video where they go head-to-head in a karate match of adorable proportions. Though they strike a mean pose with fists raised at the ready, it’s all good fun as big sis throws a “punch” and little Haru falls over dramatically. Their viewers, understandably, are just loving it.

“They’re so cute!”
“I love the little brother’s stance.”
“Older sister is like an instructor lol”
“I had to smile watching the little brother falling over while going ‘Ohhh!'”
“It’s like Street Fighter! Haha. Too cute!”

If you can’t get enough of these little munchkins, you’re in luck – father @MakotoOnodera regularly posts video of the two’s antics on their Twitter, so be sure to give them a follow!

Source, featured image: Twitter/@MakotoOnodera