In a medium non-reactive saucepan, combine the cream, green tea, and vanilla extract. Halve the vanilla beans and scrape the seeds into the cream. Add the scraped beans to the mixture and bring just to a boil over high heat. Immediately reduce the heat to low and simmer, uncovered, until the mixture has reduced by 1/4, about 30 minutes. Remove from the heat and cool, then refrigerate, covered, for at least 6 hours and preferably overnight.
Chill a medium bowl. Strain the cream-tea mixture into the chilled bowl, and beat until stiff peaks form.
In the top of a double boiler over barely shimmering water, combine the confectioners' sugar, egg yolks, and eggs, and cook, whisking constantly, until the mixture forms a ribbon when the whisk is lifted from the pan, 12 to 15 minutes.
Transfer to a mixer bowl and beat at high speed until lightened and pale in color, about 10 minutes. Fold in the whipped cream. Prepare a parchment paper collar to wrap around the outside of each ramekin. Generously pour the mixture into the ramekins and freeze until firm, at least 8 hours, and preferably overnight.
Remove the parchment paper from the outside of each ramekin, surround each souffle with a marinated cherry, and serve.
In a small saucepan, combine the sake, sugar, cherries, and water and bring to a boil over medium heat. Remove from the heat, cool to room temperature, and chill, about 30 minutes.