KamLAND-Zen experiment is a neutrino-less double-beta decay search experiment with $^{136}$Xe and the low background liquid scintillator (LS) detector. In order to suppress backgrounds proportional to volume, $^{136}$Xe loaded LS is stored in an inner balloon (IB) made of nylon. The IB was made as clean as possible. However, the contamination of $^{238}$U still remains, and its daughter nuclei $^{214}$Bi will be one of the largest backgrounds. Although $^{214}$Bi could be rejected by delayed coincidence tagging with $\alpha$-ray from $^{214}$Po, the tagging efficiency is not high enough due to the $\alpha$-ray absorption in nylon IB. To detect the $\alpha$-ray and tag $^{214}$Bi, we are planning to use a scintillation film for the IB in a future project, KamLAND2-Zen. In this presentation, we describe the performance of scintillation IB and its potential for a pulse shape discrimination.