>>50495162I'm at 2 dens that are back to back.
1) Go back and forth dropping Wishing Pieces until I get a Shellder in a den.
2) If 5 star, check if shiny.
3) If it's not 5 star, Invite Others -> Home button -> System settings -> System -> Date and Time -> turn off "Synchronize..." and move the date up one (if I reach end of month, set date to 1 and move month up one, same thing for year with the months) Exit den and re-enter
4) If not 5 star again, repeat 3.
If checked 5 star isn't shiny, Home -> Close software -> Start game -> start from beginning on other den.