Where do you get these phone cards? I have heard of them but no luck finding them.
Side missions from Naiowu store owners which are time sensitive and trigger after you've done certain main story events. So to trigger these, after completing whatever said main story events, you have to walk around the usual streets and then when you see the store owners/clerks in front of their store, if the square button icon is suddenly yellow with an exclamation point, that means that side mission has been triggered and ready to begin. Take too long to complete it however, and you'll fail the mission:
"Stonehead Haircuts' Phonecard - for example was doing a mission in Naiowu for the local barber at his barber shop who wanted you to find a young female to act as a model for him to try out a new haircut design. You find this girl walking along New Paradise by the Golden Goose gambling area. She flirts with you and then you ask her and she says okay. Then she gets a weird new hairstyle by the barber and as a thank you, he gives you the phonecard.
"Liu Jiao Shrine Phonecard" - for example was doing a mission for the shrine maiden dressed in red and white: Lin Shiling, who had some old pamphlet stolen from her and you have to recover it by first finding Ren and asking him what would he do if he stole something (to which he says he'd pawn it off) then you find it at a pawn store but the clerk wants 200 yuan for it. You pay it, then give it back to Lin and then she gives you the phonecard.
Both of these missions will give you the Black and Silver Satin Jacket
I assume the current one I'm trying to do; the collect the herbs for the drug store clerk, will get you "Termite Mushroom Phonecard"
"Elephant Phonecard" - not sure when or where that side mission is but its part of the above one; meaning both of those will get you the Red and Silver Satin Jacket.
Other Naiowu side missions yield other rewards like the yellow rubber duckie the little girl gives you that runs the book stand gives you because you recovered her yellow panda toy that a boy stole from her and hid.
Getting the duckie along with already obtaining the seagull capsule toy, BIG Interplanetary Bomber and Missile Destroyer (forget where I won or bought those two) will win you the "Let's Forklift" T-Shirt
Not sure what that one girl visiting by the Naiowu docks (the shopping list one) gave you or the Naiowu hotel manager (for the skipper mission) one because I messed both of those up; but those were not phonecard missions.