Ketai is a Japanese term that refers to mobile phones and other handheld devices used for communication, entertainment, information gathering, banking services, etc. It has become an integral part of everyday life in Japan, with over 50 million users by 2000. Ketai devices offer many benefits such as convenience, affordability, portability, access to a wide range of content, and security features such as fingerprint scanning. There are many different types of ketai devices available on the market today including smartphones, feature phones, tablets, portable media players, gaming consoles, smartwatches, virtual reality headsets and drones. Using a ketai device is straightforward and they can be used for activities like texting friends/family members; streaming music/video content online; browsing news sites/social media networks/online stores/apps; playing games online/offline/virtual reality experiences; ordering food delivery services; checking bank accounts; tracking fitness goals via health apps; flying drones via drone control apps.