The “Seirai 10th Anniversary POP-UP SHOP,” celebrating the 10th anniversary of Seirai’s artistic career, is here!

Held on the 8th floor of Yurakucho Marui from Thursday, September 10, 2026, through Wednesday, September 23, 2026, the event will feature new merchandise featuring original illustrations from *Gachikoi Nenchaku-ju: I Want to Be a Streamer’s Girlfriend* and *Roshiki Rei’s Theory of Ghost Marriages*, as well as events such as autograph sessions, photo sessions with the artist, and message board events.

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Details on the “Hoshikuru’s 10th Anniversary POP-UP SHOP”

A pop-up shop celebrating the 10th anniversary of artist Seira’s career—known for works such as “Gachikoi Stalker: I Want to Be a Streamer’s Girlfriend” and “Ryo Shiki Rei’s Theory of Ghost Marriage”—will be held on the 8th floor of Yurakucho Marui! The event will run from Thursday, September 10, (Thu) through September 23 (Wed).

In addition to a wide variety of new merchandise featuring original illustrations from both works, the event will feature special 10th-anniversary activities such as a signing session, photo sessions with the artist, and a message board event. Operating hours will follow the mall’s regular hours, except on the final day, when the shop will close at 6:00 PM.

Please note that on Thursday, September 10, the merchandise area is expected to be crowded, so admission will be limited on a first-come, first-served basis. Digital tickets will be distributed via the LINE app “mogily,” and registration opens on Monday, September 7, at 6:00 PM. Once admission for pre-registered guests is complete, free admission will begin.

Admission for other dates will generally be on a first-come, first-served basis; however, depending on crowd conditions, entry may be restricted using digital or paper numbered tickets. The start time for first-come, first-served admission each day will be announced on the day of the event via THE Chara SHOP@Yurakucho’s official X account (@thechara_yrkc).

“Ryoshiki Rei’s Theory of Ghost Marriage” Volume 2 Release Commemorative Signing Event

To celebrate the release of Volume 2 of “Ryoshiki Rei’s Theory of Ghost Marriage,” a signing event featuring author Hoshi Rai will be held on Sunday, September 20, 2026, inside the merchandise area on the 8th floor of Yurakucho Marui! From Thursday, September 10, through Tuesday, September 15 (Tue), customers who spend 5,000 yen or more at the POP UP SHOP merchandise area will receive a raffle entry ticket for the signing event.

The raffle registration period runs from 11:00 AM on Thursday, September 10 at 11:00 a.m. through September 14 (Mon) at 11:59 p.m. Winners will be announced sequentially starting at 6:00 p.m. on September 15 (Tue). The application URL will be printed on the raffle entry ticket. Winners must purchase Volume 2 of *Luo Seirei’s Theory of Ghost Marriage* on the day of the signing event, and and payment must be made on the day of the event.

Signatures will be written on a designated mini-card, and in addition to the signature, Ms. Seirai will draw one character of your choice. Eligible characters are Ryoshi Rei, Genjo; and from *Gachikoi Stalker: I Want to Be the Girlfriend of a Streamer*: Subaru, Cosmo, Ginga, Hina, and Kotono—for a total of 7 characters.

On the day of the event, you must bring a smartphone capable of displaying your e-ticket, as well as a photo ID that matches the name displayed on the ticket. Physical contact, such as handshakes, is prohibited, and gifts will be collected in the “Gift Box” inside the venue; perishable items, homemade foods, foods requiring refrigeration or freezing, and congratulatory flower arrangements such as flower stands will not be accepted.

“Serious Love Stalker” COSMIC 2-Shot Photo Session

The “COSMIC 2-Shot Photo Session,” where you can take photos with character panels from “Gachikoi Nenchaku-juu: I Want to Be a Streamer’s Girlfriend,” will be held on Sunday, September 13, and September 16 (Wed) from 1:00 PM to 5:00 PM at the merchandise venue on the 8th floor of Yurakucho Marui. Choose your favorite character panel from Subaru, Cosmo, or Ginga, and staff will take a two-shot photo for you.

After the photo session, you’ll receive a physical instant print of the two-shot photo and a bonus hard card case on the spot. Participation requires advance registration; you must apply for a “Two-Shot Photo Session Participation Ticket with Hard Card Case.” Each ticket entitles you to one two-shot photo session.

The application period runs from 6:00 PM on Tuesday, September 1, 2026, to 11:59 PM on Saturday, September 5, 2026. Results will be announced sequentially starting at 6:00 PM on Sunday, September 6. Registration with Livepocket-ticket- (free) is required to apply, and payment is accepted via credit card only. Since applications are not processed on a first-come, first-served basis, applicants must complete the process themselves within the application period.

Please note that you must bring your e-ticket and a photo ID on the day of the event. If the name on your ID does not match the name registered with Livepocket, you may be denied entry. Retakes for photos will only be permitted if there is an issue with the two-shot photo; touching the character panels is strictly prohibited.

Message Board Event

Message boards, sticky notes, and pens will be provided at the venue. You are welcome to write and post messages of support for the series, the characters, or Ms. Seira, or your thoughts on the event.

The number of cards and pens available at the store is limited, and depending on crowd levels, ample writing space may not be available. You may also post cards written at home, but in that case, paper no larger than approximately 7×7 cm is recommended. Since display space is limited, if the number of messages exceeds the planned capacity, messages may be replaced, or the display area may close to new submissions.

Purchaser Benefits & Raffle

During the event period, for every 3,000 yen (tax included) spent in-store, you will receive one random “bromide” from a set of 10 varieties. The size is L-size, and you cannot choose the design.

Additionally, for every 3,000 yen (tax included) spent, you can participate once in a raffle to win a prize of your choice. The prizes consist of two types: an “Acrylic Piggy Bank” (1 design / H60mm × W90mm × D45mm) and “Square Glitter Acrylic Art” (1 design available / 128mm × 128mm). You can choose your preferred prize, but if it is out of stock, it will be shipped at a later date.

Special offers and prizes are available while supplies last and cannot be exchanged or resold. Please note that you cannot combine partial amounts from separate transactions.

Event Merchandise

At the venue, 9 new types of merchandise from “Gachikoi Stalker: I Want to Be a Live Streamer’s Girlfriend” and and 7 new types from “Ryōshirei’s Theory of Ghost Marriage”! In addition to classic items like Cheki-style cards and pins, the lineup also includes stage dioramas, rubber desk mats, and mini acrylic art pieces.

Gachikoi Stalker: I Want to Be a Streamer’s Girlfriend

A total of 9 types of merchandise featuring newly drawn illustrations from “Serious Love Stalker: I Want to Be a Streamer’s Girlfriend” will be available! The random-selection Cheki-style cards, Photogray-style stickers, and pins are each available in 7 varieties, and sets are also available for purchase.

Lu Se-ri’s Theory of Ghost Marriage

A total of 7 types of merchandise featuring original illustrations from “Lu Se-Rui’s Theory of Ghost Marriage” are now available! The Cheki-style cards come in 5 random designs, and the lineup includes plate keychains, acrylic figures, a hard card case set, and ID-photo-style stickers—each available in two variations.

*Event details and product designs are subject to change without notice.

Purchase Limits and Defective Product Exchanges

Purchase limits apply only to new products being released at this event. For open-packaged items, the limit is 3 per type per transaction; for items marked “random,” the limit is 21 per item per transaction (up to 3 sets if purchasing as a set).

Exchanges for defective items are limited to those recognized as having initial defects, and must be returned within two weeks of the event’s end. Used items, promotional giveaways (non-sale items), minor scratches, dents, or printing irregularities that do not constitute clear defects, or items for which proof of purchase at this event cannot be provided are not eligible. Since you must present your receipt to exchange an item, please be sure to keep your original receipt.

We accept cash and various credit cards. You are responsible for keeping your own valuables safe at the venue; the organizers and venue will not be held liable for any loss or theft.

The “Seira 10th Anniversary POP UP SHOP” opens on September 10!

Frequently Asked Questions about the “Seira’s 10th Anniversary POP UP SHOP”

When is the event, and where is it being held?

It will be held from Thursday, September 10, (Thu) through September 23 (Wed) on the 8th floor of Yurakucho Marui. Operating hours follow the mall’s schedule, except on the final day, when the shop closes at 6:00 PM.

Do I need a numbered ticket on the first day?

On Thursday, September 10, entry will be limited on a first-come, first-served basis, and digital numbered tickets will be distributed via the LINE app “mogily.” Registration opens at 6:00 PM on Monday, September 7. Free entry is planned for other dates, but entry restrictions—such as the distribution of numbered tickets—may be implemented during peak times.

How can I participate in the autograph session?

If you purchase merchandise totaling 5,000 yen or more between Thursday, September 10, and Tuesday, September 15, you will receive a ticket to enter the lottery for the autograph session. The lottery application period runs from Thursday, September 10, at 11:00 a.m. through September 14 (Mon) at 11:59 p.m. Winners will be announced sequentially starting at 6:00 p.m. on September 15 (Tue). Winners must purchase after purchasing Volume 2 of “Ryokirei’s Theory of Ghost Marriage” on the event day.

Which characters are eligible for the two-shot photo session?

Subaru, Cosmo, and Ginga. With each participation ticket, you can enjoy one two-shot photo with the character panel of your choice. After the photo is taken , you will receive an instant photo (physical print) and a bonus hard card case.

How do I receive the purchaser’s bonus?

During the event period, for every 3,000 yen (tax included) spent in-store, you will receive one random bromide (out of 10 total designs) and be eligible for one entry into a raffle. You cannot choose the design, and the bonus items and prizes will be available while supplies last.

Is there a limit on the number of merchandise items I can purchase?

For new products debuting at this event only, purchases of “open” items are limited to 3 per type per transaction, and purchases of “random” items are limited to 21 per item per transaction (up to 3 sets for set purchases).

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Please check the official website for details.
*Please note that the information in this article may be outdated. We apologize for the inconvenience, but please check the official website for the latest information.

© Seira/CoreMix