  Over the 3-year active period from 2008 September to 2011 November, the
outburst behavior of the Be/X-ray binary A 0535+26 was continuously monitored
with the MAXI/GSC and the Swift/BAT. The source exhibited nine outbursts, every
binary revolution of 111.1 days, of which two are categorized into the giant
(type-II) outbursts. The recurrence period of these outbursts is found to be
$\sim115$ days, significantly longer than the orbital period of 111.1 days.
With the MAXI/GSC, a low-level active period, or a "precursor", was detected
prior to at least four giant outbursts. The precursor recurrence period agrees
with that of the giant outbursts. The period difference of the giant outbursts
from the orbital period is possibly related with some structures in the
circumstellar disc formed around the Be companion. Two scenarios, one based on
a one-armed disc structure and the other a Be-disc precession, are discussed.
