This is part of the story and therefore unmissable. If you are reading the solution though, then you are probably lost like I was. The steps for this part of the story are:
You will go to Heartbeats bar (1)
and get in a QTE fight. Then you will be told to look for Charlie.
Ask the guy working on his Bike (2)
and he will tell you Charlie is often at the Jacket place. Go to the Jacket place (3)
and you will be told he is always talking about a tattoo, but you won't get more information.
Next talk to the lady at Hokuhoku Lunches (4)
and she will direct you to Nagai Industries (5)
. Go in and ask upstairs, someone will inform you he walks around after 7PM. Once 7PM comes along, he near You Arcade (6)
and you will run into someone in a cutscene and have a fight.
After the fight, you will be told about a tattoo parlour, but not the location. Head into You Arcade (7)
and ask the 2 guys sitting down. One of them will tell you about the tattoo parlor if you say you will join them (you won't actually join them, just using the option so you can progress). Now head to Heights Okayama room 202 upstairs (8)
and talk to the owner. He will tell you to come back tomorrow. So head home and sleep when you can (must be 8PM to sleep).
Unfortunately they do not open until 2PM, so you will have to kill some time. Once it hits 2PM, head back to the tattoo parlor (8)
and you will get a cutscene, then pull back a curtain to reveal Charlie and a QTE. (Left, then X to complete it). After the QTE, you will get the trophy.