Money is important in NEO: The World Ends With You. It's used to purchase Pins, threads, and food. That's your battle abilities, equipment, and stat boosts — all required for surviving the Reaper's Game. The main way to acquire this money is by acquiring special Yen Pins from defeated enemies and from quests. The only use for these pins is to sell, and the game even has an unlockable ability that sells these pins automatically as you acquire them.
In this game, it's possible to increase the maximum money you can hold twice. This is important, as some threads and Pins will end up costing more money than you can actually carry at the beginning of the game.
How To Upgrade Your Wallet
Like most of the abilities you acquire in NEO, upgrading your wallet is done through the Social Network menu. There are two characters associated with wallet upgrades and they both require you to complete their side quest in order to unlock their nodes.
The first side quest is available on Week 2 Day 2 and involves Eiru, a popular broadcaster who has a very high-pitched voice. The second side quest takes place on Week 3 Day 2 and involves Hide Takenouchi, who is Eiru's agent.
Completing Eiru's Quest
On Week 2 Day 2 you will find Eiru standing near the Modi building in the Tower Records Shibuya area. Start his quest, which involves Imprinting some positive thoughts into his head. The beginning of the quest will give you all the keywords that you need.
There are multiple word combinations that will help Eiru get over his problem. One option is to Utilize his Difference and another is to Reject his Complex. Either way, completing this quest will earn you five FP and unlock Eiru's node on the Social Network.
This allows you to purchase the ShibuPay Expansion in order to upgrade your digital wallet for the price of four FP, letting you store up to 999,999 Yen.
Completing Hide Takenouchi's Quest
One week later, you'll find Eiru and The Prince at Tsutaya O-East, soon joined by Takenouchi. Talk to them to start this quest, which involves using Fret's Remind ability to solve a dispute between the two celebrities.
First, use your Scan ability to read the thoughts of all three individuals and then use Remind when prompted.
The right thumbstick should be pointed to the upper-right, and the left thumbstick pointed to the lower-left — it's one of the more fiddly and precise ones in the game.
Read Takenouchi's mind after this to resolve the dilemma and complete the quest. Your reward is five FP and Hide's Social Network node, which has another ShibuPay Expansion ability attached to it.
Having both of these upgrades will allow you to store up to 9,999,999 Yen once purchased. Naturally, Takenouchi's node can be found connected to Eiru's node.