This Day Ends with You! (Another Day)

Spoiler warning: Plot and/or character details follow.

Another Day is the extra chapter of the game that becomes available after completing the main storyline. It opens with the following disclaimer:

"The tale you are about to experience depicts a world entirely separate from that of the main story."

However, the Secret Reports, particularly numbers 20 to 22, make it clear that it is connected in an almost fundamental way: the Composer fled to a parallel world at the end of the second week, and this is the world he fled to.

Features

The primary difference to the other chapters is the lack of any sense of progress. However, there is a Tin Pin-related subquest in the chapter. In the course of completing it, the player can acquire several rare pins. Despite this, in this alternate world, the options open to players are intact (i.e. shops, Noise battles, etc.).

The entire Shibuya River is off-limits until after the first two events in the Tin Pin quest, while Pork City is available beforehand and after Neku awakens again in the Scramble Crossing after defeating the Wizard of Slam. Sanae Hanekoma's shop (WildKat) is open before seeing him at Pork City, but closed afterwards. Naturally, leaving and returning to Another Day resets all of this. The Shadow Ramen shop cannot be accessed in Another Day until the Wizard of Slam is defeated and Neku is sent back to the Scramble Crossing. Coming to Shadow Ramen beforehand will have Neku say that the shop is empty, then leaves. After the subquest is completed, the same will happen, but Makoto will appear and open the shop.

In the Room of Reckoning is the Composer from the main story's world. He challenges Neku to an 11-chain battle of story bosses, and victory is rewarded with a set of pins, as well as the pins and PP gained from the battles themselves. This challenge can be repeated. If the difficulty is set to Hard or Ultimate, the time taken to complete the 11-chain battle is entered into the Final Time Attack.

Tin Pin subquest

Interim

Another Day begins with Neku deciding to play in the Tin Pin Slam-off to ward off his "emo urges". Before doing so, the player can practice against several NPCs:

Also, the following can be encountered, but will not play Tin Pin:

The event sponsor - Tipsy Tose Hall
Joshua - Udagawa Back Streets
Sho Minamimoto - Miyashita Park Underpass
Megumi Kitaniji - Towa Records

First event

To progress, the player must go to Molco to sign up for the Slam-off. After the preliminary rounds, it turns out that the event was a setup by Uzuki Yashiro, Koki Kariya and Yodai Higashizawa to steal the competitors' pins, though Neku manages to retain his. Shooter then tells Neku to go to the "secret hideout", which is Ramen Don in Dogenzaka.

Second event

After a prolonged discussion, the idea is proposed that Neku, Shiki, Beat, Joshua and Shooter should go out and play Tin Pin to draw attention to themselves, in order to flush out the Black Skullers. From now on, the player can enter Shibuya River, but can no longer enter Pork City. Restarting the chapter resets this.

The following NPCs are available; victory is rewarded with a valuable pin:

The Prince - A-East (Lady Luck pin)
Pin Prof - Concert Stage (Tin Pin Shiva pin)
Mina - Shibukyu Main Store (Sparkle Charge pin)
Nao - 104 Building (Peace Full pin)
Ai - Statue of Hachiko (Lolita Skull pin)
Futoshi - West Exit Bus Terminal (Lucky Panda pin) *Warning: Futoshi can use two pins at once.
Vice Wizard of Slam, Dead God's Pad (Tin Pin Dash pin) *Warning: The Vice Wizard of Slam can use three pins at the same time, all battling each other and you. Strategy includes staying away from most pins while bashing one out one at a time. Once a pin is out, it will turn into a tombstone and attempt to defeat any pin left on the field.
Itaru "Yammer" Yokoyamada - Center St. Entrance (Tin Pin Blade pin)
Mitsuki Konishi, Center St. Entrance (One Stroke, Vast Wealth pin) Warning: Konishi can also use three pins at once.
"Shrimp" - Tipsy Tose Hall (10 Yen pin)
Sota - Shibu-Q Heads (Distortion pin)
Megumi Kitaniji - Udagawa Back Streets (Long Live the Rock pin) Warning: Kitaniji also uses two pins at once.
Makoto - Molco (10,000 Yen pin)
777 - Towa Records (Lucky Star pin) Only appears directly after talking to Rhyme.

Third event

Rhyme is waiting at Miyashita Park, and will tag along after she is spoken to. Afterwards, Higashizawa is waiting in the adjacent underpass. After the resulting bout of Tin Pin, it turns out that Rhyme was working for the Black Skullers. The group decide to return to Ramen Don, where another discussion ensues. The Skullers' hideout is Miyashita Park. Returning there and defeating each Skuller in turn completes the subquest.

Tutorial Guy (5 Yen pin)
Rhyme (10,000 Yen pin)
Uzuki Yashiro (Tin Pin Rocker pin)
Koki Kariya (Tin Pin Devil pin)
Yodai Higashizawa (Tin Pin Golem pin) The player must slam twice against Higashizawa before the player receives Tin Pin Golem.

By subsequently returning to Molco, Neku can play against Shooter (Tin Pin Ifrit pin). The Wizard of Slam, AKA Shinji Hashimoto (executive producer of The World Ends With You), then appears nearby (Tin Pin Bahamut pin and the Wizard's Glasses).

After that event, the Shibuya River area closes again.

Pork City

Pork City be accessed before or after the Tin Pin side story. Entering Pork City will also cause WildKat to close for the rest of the chapter. Each of the thirteen floors has six Red Noise symbols. After defeating all the Red Noise symbols, a Pig Noise appears (two on floor 13). Defeating them and talking to the nearby Reaper allows the player to proceed to the next floor. Also, as a reward for clearing the floor, they will give you a food item.

Upon reaching the roof, Neku finds Mr. H. However, it is the Mr. H from the main story world. He is the "ultimate opponent" (AKA the superboss of The World Ends With You) referred to in the Secret Report requirement.

The Rare Fifenfrog

Trail of the Sinner, Rubicon and Trail of the Bygone are the sole habitat of the rare Fifenfrog, and only on this day.

This rare noise drops the ultra-rare Black Mercury pin. Acquiring that pin can take time because the Fifenfrog is an ultra-rare Noise. To make it easier you can save in Trail of the Sinner, Rubicon or Trail of the Bygone and fight every Noise symbol in the screen. If the Fifenfrog symbol isn't located in the area, just leave the area, go back in it and save the game again. If you find the Fifenfrog and erase it but if the player does not get the drop they were hoping for, just reload the game and the Fifenfrog will still be in the very same spot the player found it the first time.