Wednesday 7 pm is the last day to accept. If Mitsubishi MUFJ accepts their 6.35% holding then Mitsui will likely reach reach the 50.1% that will make the offer unconditional. My view is MUFJ will accept on Tuesday.
In this takeover offer, Blocking stake is only useful in preventing Mitsui reaching 90% to proceed to compulsory acquisition of all remaining shares that didn’t accept Mitsui’s offer.