Can't find Takemura on the mission "Down the Street"
Takemura is not present at the mission marker, the mission marker indicates a location near a barrier that you need to go to and then "use" to wait for Takemura to arrive.
You need to go down to the docks (which is on a very low level, underneath the main city but the sky is still visible) and then lean against a barrier at the mission marker. This will start a conversation with Takemura when he arrives.