Gomene!umm....I'm not sure how to improve your stories but usually I heard from my friends is that try to write or provide more information like...
Without Info Example: I'm playing toys with my sister!
With Info Example:I'm playing toys with my sister in my room,when we were playing the toys we were so happy!
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I hope that you could understand what I say, cause when it comes to telling or giving advice to someone I'm not really sure about it ^_^
Gomen!