Created: 27 October 2014 · Last edited: 16 October 2026

Sensational! A flip keitai by Sharp running Android! Well, kind of... Because it is a heavily modified version of Android 4.4 KitKat lacking Google Play and the ability to side-load apps.

Part of AU's Spring 2015 collection, the Aquos K — "K" as in "keitai" — SHF31 comes in the traditional elegant and beloved flip form: a 3.4-inch screen but now with qHD resolution of 960 x 540 pixels (328 ppi), a number pad and a touch cruiser EX (incl. on-screen pointer), touch screen, and a relatively good camera.

While in the not so distant past it was flip keitais that had the stunning camera, this has changed with the most recent garake models. The Aquos K camera is somewhere in between: it has a 13.1 megapixel CMOS sensor and comes with features found on Sharp smartphones, e.g. real-time HDR, NightCatch, Framing Advisor, Translation Finder (automatic translation using the camera viewer), etc. It even features voice-activated shutter.

The Aquos K is powered by a Snapdragon 400 (MSM8926) quad-core processor clocked at 1.2 GHz, has 1 GB of RAM and 8 GB of ROM, which can be expanded up to 32 GB using microSDHC memory cards.

Supported frequencies are: 4G LTE (800 MHz and 2 GHz) and 3G (2 GHz), where an au Nano IC Card is required for cellular connectivity. Also included are Bluetooth 4.0, Infrared, Wi-Fi b/g/n, OneSeg TV, Mobile Wallet (but no NFC). Wi-Fi tethering is supported for up to 10 devices. This keitai is water-resistant (IPX5 / IPX7) and dust-resistant (IP5X).

Battery capacity is 1410 mAh. The phone measures 51 × 113 × 16.9 mm (thickest part about 17.4 mm) and weighs 128 grams. It is available in red, white, and black.

If you look at the specifications list, neither the Sharp nor the AU KDDI website mention Android. However, in the announcement of the new model, KDDI's President, Tanaka Takashi, described it as "smartphone in the form of a feature phone". To substitute the lack of Google Play, the Aquos K has the au Smart Pass service, which is in fact a menu listing applications made available to download and install by AU for their Android line of smartphones (AU were the first in Japan to release an Android-based smartphone, the IS01 in 2010). The Aquos K au Smart Pass menu will feature applications that have been optimised for its screen and will also offer support options to its users.

The Aquos K SHF31 was released on 20 February 2015. Since it was released before au's SIM-unlocking programme came into effect for new devices, it cannot officially be SIM-unlocked and is therefore tied to the au network.