Hitori is my best friend, she always helps me.

Hitori is my best friend.

I went to see a movie by myself.

It takes courage to take a step forward.

She was a secret kunoichi (female ninja).

He threw a handful of sand into the sea.

He missed a once-in-a-lifetime opportunity.

"Once in a lifetime" means to cherish the encounter that happens only once in one's lifetime.

He was focused on his work all day long.

No one knows what he did to spend one day.