Chuhai is a cocktail containing the Japanese alcohol called shochu, soda, and any kind of fruit juice. In the Tokyo area, we sometimes call it Sour instead of chuhai. This cocktail is very popular in Japan, commonly served in izakaya-style restaurants and restaurants that cater to Japanese salary workers.
Gather all the ingredients. Combine ½ cup club soda, ¼ cup shochu, 1 Tbsp Homemade Simple Syrup, and 1 tsp yuzu juice (extract) in a glass and mix well.
Add ice cubes and 1–2 tsp Korean citron tea (yuja cha) (optional) and mix well.
Garnish with a slice of lime, and serve immediately.
To Make the Simple Syrup
Bring ¼ cup water to a boil in a small saucepan. Dissolve ½ cup sugar into the boiling water, stirring constantly. Once the sugar is dissolved completely, remove it from heat and let cool completely and thicken.