A water-based ballpoint pen including a specific aqueous ink, a ball, a ballpoint pen tip that holds the ball at a front end of the ballpoint pen tip, an ink follower following the ink with consumption of the ink, and an ink container directly containing the ink and the ink follower. The ink container communicates with a rear portion of the tip. The ink follower includes at least a base oil and a thickener. The ball point pen tip discharges the ink from the top end portion. The ink container supplies the ink to the tip.