1) We recommend wine glasses because we have gin and tonic glasses here in Belgium but not in Korea! (You can use both red and white wine glasses)
2) Put one ice the size of a ping-pong ball (a large chunk of ice for gin and tonic) into each of the two glasses.(If there is no ice as big as a table tennis ball, use ice cubes I put 3 ice cubes in each wine glass, so 6 ice cubes in total)
3) Next, place 2 dried orange shreds in each glass
Pour grapefruit soju into each glass of soju.
Cut the grapefruit. Prepare two roundly shredded pieces.

4) Draw a half-knife cut grapefruit of 3 and hang it on the glass, and squeeze the juice of the two cut grapefruit into each glass first and then put it in.
5) Lastly, put the cocktail spoon in the glass, pour the tonic into the cocktail spoon, and insert a cocktail straw to complete it
(If you don't have a cocktail spoon, it doesn't matter if you just pour it, but then the tonic splashes into the glass, making the glass look less clean.)
! If you don't have a cocktail-only straw, cut the regular straw with scissors

If you don't like grapefruit, you can add orange