Nintendo has announced its first smartphone game, Miitomo, with a release window of March 2016.

The game centres on the Wii and Wii U's Mii player avatars, which engage in a chat-based mechanic.

Upon creation or import, players' Miis start conversations with them using a range of "friendly conversation starters," such as talking about the player's hobbies.

Answers given can be shared amongst the player's friends.

Nintendo president Tatsumi Kimishima explained that with Miitomo, "you may be able to find out unknown aspects about your friends or unexpected commonalities you share with your friend, because Miitomo may pick up the topics that you usually do not discuss but would be willing to answer if asked."

"What we would like to realise is, through such communication, you will be able to deepen friendly relationships and have more people with whom you can play games."

Nintendo describes the game as "free-to-start," implying that in-app purchases will be present - possibly for custom clothing options and the like.

Miitomo will be the first game Nintendo has produced for hardware other than its own, excepting a couple of minor Flash titles in the mid-2000s.

Four more Nintendo mobile titles are planned for release by March 2017.