This tiny phone is Sharp AQUOS mini SH-M03 which probably will not be avable outside of Japan.
It’s little phone 126x66x9mm with 4.7″ full HD screen. Aditional advantage are slim frames, but… there is always some “but” this means that system keys are on screen and front camera is under screen.
With small size comes… great insides: heart of phone is Snapdragon 808 with Adreno 418 graphic, 3GB of RAM, 16GB of internal storage and handling of up to 200GB microSD cards.
Phone is running under Android 6.0. have 2810mAh acumulator, it’s dust and waterproof, comes with mobile wallet features and one seg TV, plus early earthquake warning and is priced around $523.