Mikuru Asahina is the shy and timid 4th member of the S.O.S. Brigade. She is extremely cute and is oftentimes harassed by it by Haruhi. Turns out, Mikuru is actually a time-traveler from the distant future that was sent to investigate the mystery behind the inability to travel to any point in time before three years prior to the present story. Mikuru owns a device called the TPDD (short for Temporal Plane Destruction Device) which acts like a time machine which allows her or anyone she wishes to the past or the future but not 3 years before the present story.