Artist wrote:

すなあそび。

いっしょに おしろ つくろう？

Something along the lines of,

"Let's make something in the sand together?" or something like that.

Schrobby said:
Artist wrote:

すなあそび。

いっしょに おしろ つくろう？

Playing in the sand.

Shall we make a castle together?

Moonspeaker said:
Playing in the sand.

Shall we make a castle together?

See? And this is why I need to study more. Thank you sir.