A Certain Magical Index/Tear Jerker

There some moments in this series that will just make you cry.
 * Episode 6, when Index discovers from Touma's doctor that
 * Also a Crowning Moment of Heartwarming: "Touma... don't you remember? Index... Index... loved you, Touma..."
 * This troper was reduced to tears watching Touma's You Shall Not Pass moment with Mikoto.
 * Episode 17, Touma trying desperately to save his father from getting killed, only to get his ass handed to him.
 * Episode 20,
 * Volume 14,
 * In Volume 16,
 * Volume 20 has the scenes with Accelerator, Last Order and Misaka WORST. Seeing Accelerator is absolutely heartbreaking.
 * Even earlier in the volume we get the scenes in the train, with Last Order exhausted, barely able to speak and move, and Accelerator breaking inside because there's nothing he can do to ease her pain. His despair and anger about the unfairness of the situation is just heart rending.
 * Volume 22 light novel