Pokémon Mystery Dungeon: Red Rescue Team Tips

Oh I Wish Upon a Jirachi
Go to Wish Cave and on the 99th floor you should encounter a Pokemon named Jirachi. Defeat it and it will want to join your rescue team, but you might not want that outcome just yet. You still have the Wish Stone afterall, and Jirachi will not grant any wishes if you recruit it. If you choose to decline the rescue team offer, the Wish Stone will wake Jirachi, and you will be given a choice of what you want -- lots of money, all the money from Wish Cave, lots of items, all the useful items from Wish Cave, a friend area, one of the friend areas you do not have yet, more strength, an item that will raise your stats, or something good. A new pokemon will join your rescue team or your rescue rank will increase. If you choose something good, you will leave the dungeon and be woken by your partner the next day who will cheerfully inform you about some great thing that just happened, little realizing that it was Jirachi's doing.