The World Ends with You/Day 4: Erased

104 Building
Mission 4: Reach Towa Records. No time limit. Fail, and face erasure.

After a fairly long scene with Shiki, Beat(finally calm with Phones around) and Rhyme, talk to them to obtain (S) Noise Report.

Skulls and Rhyme will race you, but ignore it. Simply go to 104 and do some shopping. Choose and read all choices Shiki and Eiji Oji, the Prince(AKA Mr. Spicy Tuna Roll) has to chat about with trends, clothing and other stuff. After, you obtain (S) Brand Awareness and (B) Shop Quests.

Before you go, you can find a Green Noise (5000 Yen) on the left side of this area.

Scramble Crossing
When you arrive there, you will obtain (B) Green Noise Symbols, (B) Pin Growth/Evolution. This lets you learn about Pig Noise. Now move down a bit and scan for a Green Noise, defeat the pig for Love Charge. Head east to meet a Reaper telling you to get him two 1000 yen pins. If you're having trouble, erase Bigbanfrogs.

Obtain (S) Extra Slot, (S) Chain 4, and 5,000 Yen.

Shibu Dept. Store
Shibu's stores are REALLY expensive here, so think twice before going inside.

There's a guy named Makoto with his girlfriend Ai(or maybe it was Mina, ah w/e). You can talk to them if you want. Well, enough about them. Talk to the Reaper and give him 500 yen pins to pass through. You will get (S) DEF Boost, (B) Chained Battles, and 5,000 Yen. You may try to chain Noise, but save your game before you try that.

Cadoi City
Go east and you can find Skulls and Rhyme at the entrance of Towa Records. Speak to them for an event. After,you will get (S) Mingle Mode, which lets you trade Friend Cards and earn PP. Check your Phone for details.

Save and check your pins before entering Towa Records.

Towa Records
Upon entering Towa Records, there will be a scene and then a battle from which you get the pin: Lightning Moon. Another scene and then comes the day's boss battle.

Boss

 * Swing Shark

Obtain (S) ATK Boost, Masamune, Scarletite.