Achiral molecule of N-methyl-3,4-bis(diphenylmethylene)succimide (1) was found to form a chiral crystal, in which two inner phenyl groups (a and a’ of 1 shown in Scheme 1) are overlapped and therefore chirality appears depending on whether a or a’ is above. The chirality of 1 in the crystal was frozen by photoirradiation in the solid state to give an optically active photocyclization product (2).