Endeavor was in his Agency's office when his phone rang, picking up he saw something unexpected on its screen: his youngest child's id. Why would the 'I never pick up your calls' Shoto call him? That was very strange, so to learn more, he took up the call.

"Hallo? What is it Shoto? It's Enji." spoke the older Todoroki.

"Afternoon Father. Midoriya-kun suspecting that I supposedly have a twin sibling because my Quirk is too perfect as he says." replied his son through the phone.

"Twin sibling?" asked Enji before something clicked in his mind. The Quirk Reproduction Rule Six: if twins born and the older creates an entirely new Quirk, the younger replicates it either just as well or maybe worse. Variations include more refined variants, stronger Quirks or even weaker ones if that is healthier to the owner. However, if the younger sibling makes the new Quirk, and the older didn't, then this won't happen.

"Yes, that's what he thinks. I think this is illogical." reminded the younger Todoroki as he also said his opinion.

"I'll investigate about it. Goodbye." declared the breadwinner and as his son responded, they ended the call.

'Let's see what I remember before Shoto's birth.' thought Endeavor as he remembered at the time his wife's fourth pregnancy reached the period where the fetus was recognizable. Then he found the fragment of memory from the time he was still a little caring with the sentence: Two? A question he probably blurted out in surprise. Then something sank in, a terrible realization.

"Oh no. No. No. No! No! No! No! NO! NOOO!" his rapid fire no saying reached the point of limit where even the walking in Burnin jumped in fright.

"Yikes! Is something wrong boss?" asked the young woman from her superior and the latter's attention turned to her with fierce determination, one far more burning than the one he had before All Might's retirement.

"Burnin! Get the team! We have a serious case to be checked! I want to know every child who born at the day of January's Eleven in the age of my son's! We have to check that hospital! We have to find them!" barked his order furiously and strictly the man.

"Yes sir! But whom are we looking for?" asked meekly the Sidekick.

"My son's lost twin sibling!" declared the man as he started to leave his office.

"Uh ugh. I do as you orders." saluted the woman as she sprinted out before Endeavor could pass the door.

.

Back in U.A.

"That was fast." commented Bakugo and Midoriya on the Todoroki's phone call.

"Father said he'll investigate." told them Shoto his parent's answer and he started to leave.

"Where are you going Icyhot?" ask-barked the blond teen.

"To visit my mother." replied the asked.

"Can I join?" asked him Izuku.

"Yes, you can. Mom is interested to meet with you." answered Todoroki.

"Hey Deku! Don't forget to be cautious if you ask with Half and Half about the twin." said Bakugo.

"We'll." replied Shoto.

.

At the time somewhere in Musutafu a black suited biker in helmet without a motorbike showed up between two construction areas of two separate projects. From their right hand they released a wave of fire worthy of Shoto Todoroki's power to destroy pre-finished building on their right and from their left they recreated the glacier used against Sero on the opposite construction site. Before anyone saw them, they disappeared.