They seem..so calm

A young boy and girl, seemingly his sister, sat underneath the full moon. Speaking in hushed soft whispers they didn't notice the demon slayer behind them about to strike. What caused him not to strike was the kanji symbols in their eyes. Uppermoon 0, a myth, a legend, supposedly not true? But here they where, young enough to be around twelve and thirteen. Yet when they noticed they demon slayer. They didn't attack. Nor showed any fear. They did nothing but invite him to sit down with them.