Official anime merchandise brand COSPA has opened pre-orders for a new wave of goods inspired by the TV anime Tensei Shitara Slime Datta Ken (That Time I Got Reincarnated as a Slime), featuring protagonist Rimuru Tempest in both his human and slime forms across a range of apparel and everyday accessories.

About the Series

Tensei Shitara Slime Datta Ken — commonly shortened to Tensura — is an isekai web novel by Fuse, originally serialised on the “Shōsetsuka ni Narō” platform, with a manga adaptation by Taiki Kawakami. The TV anime launched in October 2018. A theatrical film, Guren no Kizuna-hen, opened in November 2022, followed by the three-episode special Coleus no Yume in November 2023 to mark the web novel’s 10th anniversary. Most recently, the second theatrical film Sōkai no Namida-hen opened in February 2026, and Season 4 of the TV anime (split across five cours) began airing in April 2026.

New Items at a Glance

Rimuru Tempest T-Shirt

A black tee featuring a dynamic print of Rimuru, crafted from a durable fabric with strong breathability, moisture absorption, and moisture retention. The material resists twisting after washing and allows easy on-and-off wear. Available in S / M / L / XL. ¥3,300 (tax incl.) — scheduled for early November 2026.

Rimuru Slime Thermo Stainless Mug (Baking Finish)

A blue vacuum-insulated stainless mug printed with slime-form Rimuru. The baking-finish coating is heat-cured for extra durability, while the double-wall vacuum structure keeps drinks at the ideal temperature. Shatter-resistant and portable — great for outdoor use. Size: approx. 9 cm (H) × 7.5 cm (D). ¥2,970 (tax incl.)

Rimuru Tempest Flip Smartphone Case (L / LL)

A sleek faux-leather flip case in two sizes. The rotating design lets you shoot photos without removing the case, and the clean back panel (no camera cutout) accommodates a wide range of handsets — including models with protruding lenses up to approx. 5 mm. ¥4,730 (L) / ¥4,950 (LL), tax included.

Pass Cases (Two Designs)

PU leather pass cases with snap hooks, available in a Rimuru Tempest design and a Rimuru (slime form) design. Approx. 10.5 × 7 cm. ¥1,650 each (tax incl.) Compatible with COSPA’s separately sold reel key-holder series.

Tempest Diplomatic Gift Towel

A 100% cotton towel (approx. 84 × 33 cm) printed with Rimuru, shipped wrapped in a traditional Japanese noshi-gami gift paper — perfect as a souvenir or novelty gift. ¥1,210 (tax incl.)

“Melting Rimuru” Metal Carabiner

A COSPA-original shaped aluminium carabiner featuring the adorable slime Rimuru, manufactured in Tsubame City, Niigata Prefecture — renowned for world-class metalworking. Comes with a ring for bundling keys. Approx. 8 × 5 cm. ¥1,430 (tax incl.)

“Rimuru Sandwiched in a Burger” Outdoor Sticker

The collection’s standout item: a charming sticker depicting Rimuru wedged between burger buns and toppings. Waterproof and UV-resistant, it’s designed for outdoor use on vehicles, helmets, snowboards, and more. Approx. 13 × 10.5 cm. ¥770 (tax incl.)

The same design is also available as a mini sticker set of four pieces (approx. 6 × 6 cm each) for ¥770 (tax incl.) — ideal for decorating small items or slipping inside phone cases. (Illustration by: Riz)

Pre-Order Period & Special Sales

Pre-orders are open via COSPA until 6 September 2026. Select items will be available for early purchase at the GC Novels 12th Anniversary Pop-Up Shop, running from 7–23 August 2026.

• Rimuru Tempest T-Shirt — ¥3,300 / ships early November 2026
• Thermo Stainless Mug — ¥2,970
• Flip Case L — ¥4,730
• Flip Case LL — ¥4,950
• Pass Case (Rimuru Tempest) — ¥1,650
• Pass Case (Slime Rimuru) — ¥1,650
• Gift Towel — ¥1,210
• Metal Carabiner — ¥1,430
• Outdoor Sticker — ¥770
• Mini Sticker Set (4 pcs.) — ¥770

All prices include Japanese consumption tax. Product images are for illustrative purposes; actual items may differ. Materials and specifications are subject to change without notice.