Make the blackberry yuzu juice concentrate:

Cup of Yum
1. In a small saucepan, combine blackberries, lemon juice and granulated sugar.
2. Bring to a simmer over medium-low heat, and cook for 10-15 minutes, until the blackberries soften, release their juices and the syrup thickens a little.
3. Remove from heat.
4. Place the blackberry mixture through a sieve over a bowl and push the blackberry juice through with a spatula.
5. Discard the blackberry seeds.
6. Stir in yuzu juice and set aside.

Assemble the drink:

1. In a tall glass filled with ice cubes, pour in half of the blackberry juice concentrate (about 1 ½ oz).
2. Top off with carbonated water.
3. Add in a sprig of fresh mint and garnish with a lemon slice.
4. Stick in a straw, give it a stir, sip and enjoy.