Just a single terminal. Please.

launch-sakura

#! /bin/bash
WINTITLE="sakura" # Name of the window (or part of it)
PROGRAMNAME="sakura" # Name of the program, so it can be opened if there's no window currently

# Lists all windows, if there's one containing $WINTITLE it'll return 1, and bring the current instance of the program to the front.
if [ `wmctrl -l | grep -c "$WINTITLE"` != 0 ]
  then
    wmctrl -a "$WINTITLE"
# Else, it'll launch a new instance
else
  $PROGRAMNAME &
fi

# We're good!
exit 0

http://blog.sirupsen.dk/script-fu/one-terminal-just-one/