In this study, we focused on accelerating the TTA rate constant, which has not been extensively studied before, by synthesizing a trimeric UC emission material, TAB. This material combines three anthracene molecules, which are expected to exhibit intramolecular triplet exciton hopping. We developed a TTA-UC material by combining TAB with one of the photosensitizers, PtOEP, and experimentally evaluated the TTA rate constant and the mobility of triplet excitons during the TTA-UC process using time-resolved luminescence measurements and time-resolved EPR measurements. We confirmed that the structural fluctuations driven by vibronic interactions in the TAB molecule facilitate the quick intramolecular migration of triplet excitons generated by the energy transfer reaction from PtOEP among the anthracene units on TAB, effectively increasing the TTA reactivity. The present picosecond vibronic motion is realized by introducing the symmetry breaking CT character through the boron atom in TAB. The challenge is to develop new molecules that achieve both extended triplet lifetimes and TTA reaction distances by modifying molecular designs such as introducing substituents. This new strategy of utilizing trimeric molecules that induce long-distance intermolecular TTA is promising to accelerate the development of TTA-UC materials with high light-to-energy conversion efficiency.