Chapter 3: One for all
Inko and All Might returns to All Might's cottage with All Might carrying Inko like a bride. When they reached, they were greeted by Izuku who was playing Uno with Eraserhead and Ryuku. After Inko thanked the heroes for babysitting and Eraserhead telling Izuku to not get himself into trouble, Izuku asked his mom how his date go with All Might before asking All Might if he's going to marry his mom. All Might then smiled at Inko who just laughed and told Izuku that they're not ready to commit to marriage yet. The next day, All Might continue saving people and fighting villains until a press conference came to him while he was a middle of eating at a fast-food restaurant with Inko and Izuku. Soon after answering a few questions about his upcoming project to build his agency, he confirmed that he's officially dating, causing Inko to get embarrassed and Izuku to get excited. While this is happening, multiple kids who are going to kindergarten soon are watching the confirmation on tv.
After eating, the trio went back to the cottage while Inko told All Might that she's not used to being on tv before warning him about Izuku's recklessness and mischievous behavior, which All Might scoffed at before asking his girlfriend how much a troublemaker Izuku can be. Suddenly a montage of Izuku getting himself into trouble begins starting from malfunctioned inventions that caused explosions to pulling pranks on bystanders, which All Might joins him in much to Inko's annoyance. Soon, All Might helps Izuku creates his hero costumes as he told him everything about his dream of being just like him. All Might then rubbed Izuku's head before taking him out to watch and learn about being a hero. All Might then change to his hero form and takes off to fight a sludge villain and a chainsaw villain while Izuku watches in amazement as he takes notes in his hero journal. Afterward, All Might told him that being reckless and putting his nose into people's business to help makes a true hero. Suddenly a giant villain came out of nowhere and cause a panic, causing Izuku to tell All Might that he got this as he rushed into danger and use one of his inventions called the disintegration ray, which caused the giant villain to turn into ashes before he gets a chance to step on him. All Might then clap and cheer for Izuku while the crowd and Inko just stare at him until Rock Lock whispers something in his ear.
That evening, after apologizing to the chief of police, All Might told Izuku that according to the commission, he needs to have a quirk to be a hero. But since he quirkless, it's impossible to be a hero. Izuku then pouts before giving up and said that All Might is right, so he must understand and face the fact that he'll never be a hero, causing Inko and All Might to look at each other before All Might tells Izuku to get up and tell him about his power called one for all. He then said that one for all is a transferable quirk that can be passed on from one user to the next. Its name comes from its nature; being 'one' Quirk for 'all' people. For the quirk to be transferred, the recipient must ingest a sample of the predecessor's DNA (ex. a strand of hair or a drop of blood). Izuku became shocked as All Might takes a strand of his hair and told Izuku to eat it, causing Izuku to be disgusted, which also caused Inko to assure her son that she knows that he'll make her and All Might proud with one for all. After Izuku ate the hair, Izuku gained one for all, causing Inko to take All Might to another room while Izuku does analysis on his new quirk. Meanwhile, Inko talked to All Might about Izuku's training for one for all, which All Might told Inko that the kindergarten center has basic training for quirk using so he'll be fine. Inko then sigh and asked All Might when did he get one for all from his master Nana, causing All Might to said at age 15. Inko slapped her forehead afterwards.