im looking for the yaoi manga, i forgot the title or name, i think it was new its about a ...

im looking for the yaoi manga, i forgot the title or name, i think it was new its about a yakuza guy (seme) was from the past or like he teleported in the future and the uke (mc) which is just working in a company met the seme shocked when he saw him with a gun, well thats actually what i can recall, please reply if ur familiar with it huhu plsss i need it