Remove the skin and seeds from the kabocha squash and cut into small pieces
Place the kabocha squash in a steamer and steam for 15 minutes
Puree the steamed kabocha squash until smooth and let it cool
In a bowl, combine the kabocha squash, milk, and honey, and mix well
Soak sheet gelatin in cold water, then melt it using a double boiler
Add the melted gelatin to the kabocha squash mixture and mix
Pour into mousse molds and chill in the refrigerator for 3 hours until set