The first fireflies of the season were spotted at Horai-en Garden (蓬莱園) at Hakone Kowakien on May 25, 2026 at 7:00 PM. Every year from late May through mid-June, Genji fireflies (Genjibotaru) naturally inhabit this lush garden nestled within the Hakone outer mountain range, filling early summer evenings with a soft, enchanting glow. The area near Horai Bridge — which connects Horai-en Garden directly to Hakone Hotel Kowakien — is considered the prime viewing spot, where visitors can watch the fireflies' gentle light while listening to the sound of the nearby stream.
Through June 28 (Sunday), the Hakone Kowakien Hotaru Festival (firefly festival) is underway under the theme "Don't just watch fireflies — enjoy Hakone until night!" A limited-period day-trip plan is available, combining admission to the hot spring baths at Hakone Kowakien Yunessun, a dinner buffet at Hakone Hotel Kowakien or Hakone Kowakien Ten-yu, and the 365-day festival plaza.
Lantern Night Returns for Two Nights Only
The popular nighttime program Lantern Night, which drew enthusiastic crowds last year, returns to Horai-en Garden for two nights only. Participants write their wishes on a lantern and light it together with other guests in the garden, creating a magical illuminated nightscape. All lanterns are attached with strings and fully collected after the event for environmental protection.
| Dates | June 6 (Saturday) and June 7 (Sunday), 2026 |
| Location | Hakone Kowakien Horai-en Garden (directly connected to Hakone Hotel Kowakien garden) |
| Fee | 3,500 yen per lantern (tax included) |
| Access | Directly from the 2nd floor garden entrance of Hakone Hotel Kowakien |
Note: In the event of rain or strong winds, the venue may be changed or the event may be cancelled.
Reservations and details are available at the official booking page.
Hakone Hotel Kowakien — Stay in the Heart of It All
Hakone Hotel Kowakien is a next-generation resort where guests can enjoy Hakone's hot springs, nature, and dining. Hotel guests receive unlimited access to Hakone Kowakien Yunessun and Motoyu Mori no Yu throughout their stay, including before check-in and after check-out.
A New Greenery Plan is available for limited dates through June 30, 2026 (some exclusion dates apply):
- Dinner buffet with all-you-can-eat and unlimited drinks (alcoholic and non-alcoholic)
- Unlimited access to Yunessun and Mori no Yu
- From 24,750 yen per person (standard room Type-A, 30 m², 2 guests; bath tax not included)
Details and reservations: Official booking page
