Death March to the Parallel World Rhapsody, Vol. 17 (light novel)

Satou and his friends arrive at the castle to be decorated for theiraccomplishments.
But there, they hear from Princess Sistina that the royalsymbol-the cherry blossom,
has ceased to bloom. They decide toinvestigate while sightseeing around the capital,
only to catch wind of acase they never would have expected...