Mr. Osomatsu (2022)

One day Osomatsu meets an elderly gentleman who tells him a story about his son, who he lost in an accident. Coincidentally, Osomatsu looks similar to the deceased son, and so the gentleman wishes to adopt him. The man turns out to be the CEO of a big company, and, after overhearing the conversation, the rest of the sextuplets deicide to get into a fight with Osomatsu to decide who will become the heir. Later on, the story takes a sudden, unexpected twist as three strange men dressed in black show up. (Source: osomatsu.fandom.com)