Unfortunately, neither HTC or KDDI have revealed any details of whether the HTC J Butterfly will be available outside Japan.
The smartphone features a 5-inch full-HD display and is a waterproof device. The HTC J Butterfly, much like the One (M8), runs on a quad-core Qualcomm Snapdragon 801 processor (unspecified clock speed) and 2GB RAM. It's worth noting that HTC's One (M8) (Review | Pictures) is powered by 2.5GHz quad-core Qualcomm Snapdragon 801 processor, alongside 2GB of RAM. The J Butterfly comes with 32GB of inbuilt storage, with expandable storage via microSD card (up to 128GB).
(Also see: HTC One (M8) vs. HTC J Butterfly)
It sports a 13-megapixel rear camera with dual-LED flash, while it also houses a 5-megapixel front-facing camera. Notably, the HTC J Butterfly also sports the dual rear camera setup, first seen on the 2014 flagship handset. However, KDDI calls the rear setup as "Duo Effect" camera in the press statement. The J Butterfly will be available in Rouge, Canvas and Indigo colour options.
The smartphone supports LTE connectivity (Japan's 4G LTE bands) apart from Bluetooth, Wi-Fi, GPS/ A-GPS, GPRS/ EDGE and 3G connectivity options. The HTC J Butterfly comes with a 2700mAh battery, weighs 156 grams, and has dimensions of 145x70x10mm. Further, the smartphone supports HTC's much-touted Dot View Case, which was unveiled alongside the One (M8). The One (M8) came with a 2600mAh battery.