Sticking out of the dirt, there's a cross adorned with flowers and shellfish shells. This is a tomb. The flowers and shellfish were put here as decorations and to honor the dead that currently lie under the dirt. And the cross marks the tomb, obviously.
This is a tomb, but it feels really fun (ふん). Decorated with flowers and shellfish shells, it’s not a sad place at all. It's a fun place to remember all the fun times with people you loved.