Deltarune Chapter 5 features a hidden collectible: Pink Coins. Finding at least 10 of these coins is essential for obtaining the Mysterious Key, which in turn unlocks the Pink Door leading to the chapter's secret boss. Beyond that, collecting all Pink Coins offers a special reward after the secret boss is defeated. There are a total of 19 Pink Coins scattered throughout Chapter 5.
Garden Area Pink Coins
One Pink Coin can be found near the Hopschef area. After passing the Hopschef, locate the watering can and a patch of ground. Watering the ground reveals a path leading to a river. Follow the river upstream to find a chest containing the coin. Another coin in this area is accessed by going right from the Hopschef warp. After hitting a platform-mode switch, cut the vines, defeat the Aqua enemy, and reach the top of the area. Activate the next platform-mode switch to access a door. Navigate the water section, avoiding attacks from the Tropical Starwalker, and hit the bell at the end for the Pink Coin. The third Pink Coin is near the End Of Garden warp. Head right to a platform-mode switch, then go left to fight Aqua's bullet pattern. Continue left to a torii gate, and at the end of this section, hitting the Pink Bell grants a coin.
For the fourth Pink Coin, return to the shrine where the PetalFeather was obtained (Garden: Near Shrine). A platform-mode switch now rests where the feather was. Activate it and head left, climbing leaves to reach the top of the shrine. Continue right and jump across more leaves to hit a Pink Bell for the coin.
Cliffs Area Pink Coins
To find the fifth Pink Coin, start at Cliffs: First Climb. Drop down, activate the platform-mode switch, and proceed through the platforming section until you reach another switch. To the left, use Ralsei to grab a vine. Have Susie cut it, and aim to land on a ledge that appears on the left. The Pink Bell here holds the coin. Immediately after, continue through the platforming until you encounter a Shi growing crops. Go past the crops to find a vine. Climb it, staying to the right, to reach an area where the Pink Coin floats against the rock face. Continue climbing to retrieve it.
The seventh Pink Coin is located near the Cliffs: Shop door. Navigate the wheat area to reach a space with floating flowers. Activate the windmill by interacting with it. Use a nearby flower to reach branches on the cliff face. Wait for another flower, have Ralsei hang from it, and then jump onto him to reach a ledge. Complete Seth's bullet pattern, and the Pink Coin will be available in a Pink Bell to the right.
For the eighth Pink Coin, travel to Cliffs: Netskie Climb. This coin is only available on a return visit. Head to the cave with dash challenges and complete them all to reach the Pink Bell containing the coin.
Castle Area Pink Coins
Starting from the castle's cafe, take the right exit. In the next area, knock all statues to the lower section. Return to the garden outside the castle, and go through the door to the right of the light portal. In this room, push each statue onto a button behind them to form a bridge to the ninth Pink Coin. The tenth Pink Coin is also accessible from the castle cafe. Take the right exit, then the northern exit in the following room. A chest containing the coin is visible behind a screen door.
From the Castle: Mysterious Puzzle door warp, enter the room with the Orange Door. Solve the puzzle by positioning blocks according to the paper walls. Activate the platform-mode switch and use the blocks to reach the Pink Bell on the right side of the room. The eleventh Pink Coin is yours.
To find the twelfth Pink Coin, proceed from the previous location until you reach a pillar with rotating boxing gloves. About halfway up, a paper door can be opened by having Susie hit a boxing glove towards it, stopping it, then hitting it as Kris. Enter the opened door and have Susie smash the Pink Lantern in the next room to claim the coin.
The thirteenth Pink Coin is hidden behind a door requiring five foxes. This door is north of the castle cafe. Foxes can be found in the statue room (one by catching it, another by pushing a specific statue off a ledge), in a hidden room accessed via a gap in the statue room's far wall, behind a screen in the northeastern statue room, and within the moving paws to the right of the fox door. Once all five are collected, return to the fox room to claim the coin. A fourteenth Pink Coin requires a block puzzle north of the fox door. Position the blocks as described, hit the platform-mode switch, and use the blocks and Ralsei to reach the Pink Bell at the top.
For the fifteenth Pink Coin, head to the right-hand exterior door of the castle. Follow the path leading bottom-right to an area with a Pink Coin chest and two mushroom switches. The first mushroom is easy to place. For the second, you must race a fox to place the mushroom on its switch before the fox eats it.
Other Areas and Final Coins
In Yellow's Room (the zen garden area), proceed left from the next room to find a platform-mode switch. Activate it and head right, jumping to the next room. Use a flower to ascend and find the sixteenth Pink Coin inside its bell at the top.
To get the seventeenth Pink Coin, go to the castle exterior left side via the Blue Door. Descend stairs to your bottom left and activate the platform-mode switch. Complete the subsequent platforming section, which involves enemies throwing projectiles, to reach the Pink Coin Bell.
The eighteenth Pink Coin is found on the castle ascent. Reach the room where Susie and Ralsei act independently. At the top, take the passageway to the left, which leads to a platforming obstacle course. Complete this course to find the Pink Bell.
Finally, the nineteenth Pink Coin is located near the Pink Door for the secret boss. Head to the top of the castle, just before Green's Shop, and go left instead of right. Follow the obstacle course until you reach a pit. Drop down, activate the platform-mode switch near the Pink Door, and claim the Pink Coin from the Pink Bell.