For competitions, that is a horrible period. Absolute none. Until this year we had flying robot contest in late March by now it is in October.
Most of the competitons happen in July(biped robot contests and robo-one events are mainly here), September/October and December. Spring is mostly for announcements and registrations.
Now, about events, I know about 2 that are still NOT confirmed yet. One is from a university called Tokyo Institute of Technology which willl be mainly an expo of their current projects and it should be around 16th of february. The other one is here in Tsukuba! We are preparing some expo about Cybernics(dont cofuse with cybernetics) but that should be around mid or late March.
I will see if there is anything else and post later.