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Quest: Fixing Pichu's Ukelele
After you get back to Booker's house, he notes that Ukulele Pichu has broken its ukulele. Talking to Booker will begin your first instance of a Quest, side missions that do not normally have a big effect on the story, and can all be accepted at once, unlike the previous game. They also do not overlap with Missions, so you can do them at any time. Booker asks you and Nick to get the materials to fix Pichu's ukulele. Go outside, and speak to the fisherman at the boat to return to Dolce Island. Navigate your way back to the area where you first captured Pichu, in front of a hollowed out tree stump, which is where the materials are located. Nick goes in and tries to get the materials, but accidentally disturbs six Sunkern who are in the bottom of the tree. You will now initiate a group capture. Use Poké Assists to make this a lot easier, or simply make big loops around the Sunkern, as they do not need much to fill their Friendship Gauge. Afterwards, head back to Booker and hand him the materials, and he will fix the ukulele. While heading back, Nick will notice that the Wireless Tower seemed to be flashing. After handing Booker the materials, you get your very first Quest Clear, and 10 Ranger Points!
Head out of Booker's house, then north and then northwest, to reach an area with what seem to be ruins and something that looks like an old obelisk. On this obelisk, you'll see some kind of glowing orb. Suddenly, it starts moving and scaring all of the villagers away. Once you go to investigate, it reveals itself to be Celebi. You will initiate a capture, and your first instance of a boss battle, where the Pokémon you must capture has a Friendship Gauge of a much larger size than any regular Pokémon. Avoid its attacks, but make sure to keep special attention to its vines, which will limit the area of the screen in which you can make loops. Keep looping around it to get a victory. When you're done with the capture, Celebi will envelop you in its light, and take you to the past. Here you meet Ravio. Ravio is unhappy with Celebi for randomly bringing a stranger to the past without their permission, and tells it to take you back to your time, to which Celebi complies. Then all the villagers ask about your disappearance before you continue on.
Your Partner Pokémon
Get out of Booker's house and Pichu will want to come with you to rescue its friends. And so Pichu becomes your partner Pokémon. Before you leave Booker will explain Pichu's Poké Assist. Now go east to Lapras Beach.
When you enter Lapras Beach you witness an argument. Then you are forced to catch a Lapras. After the capture, recharge if you want and talk to Nixie to go to the Coral Sea.
Go south to enter the next area. Once here catch as many Chinchou as you can because they will help later. Keep going south and go in the little room on the east after the presence of a large metal body is confirmed. Catch the Corsola over there. Use it knock down the Crumbling Wall over there.
Then go a little bit south and a Horsea and Clamperl will attack you. After their capture, a Kingdra will knock off the "U.F.O." by using Whirlpool. Now you have to chase it and retrive it. It uses Bubble and Whirlpool. After you catch up to it Kingdra will drop it.
Go south again and you will enter a dark place. Here the more Chinchou you have the brighter the area around you is. Go west the keep going south till you get the UFO. Then two Sharpedo will attack you. After the capture you will be returned to Lapras Beach.
Back on Land
The little girl examins the UFO and declares that they are called Z.Z. Flyers. Pichu also gets really angry at it.Now that was an excellent Mission Clear.
After getting the Ranger Points the little girl indroduces herself as Nema. Now go east and up the stairs and a boy should come running down. Then go to the exit from where the boy came from.