Today's Mission Quests?

How does one do the "Invade the Watermelon Field" and "Help Agent E" quests? I've done the "turn in watermelons" quests before with that quest being my Today's Mission, but I don't get the Secret boxes. I have no idea on the "Help Agent E" one, though. :/

Each day, you get a new mission. Missions include such things as getting 50 total points on a speed quiz, turning in 20 Master M Reports, Turning in Intelligence Documents, or Collecting an Agent Badge.

Let's say your Today's Mission quest is to help Agent E. Get 20 Master M Reports from monsters, and turn them in to Agent E. When those have been turned in, you will then have a lightbulb above your head which will give you the secret box.

Just do the task that the quest says to do, and you get a secret box.

Also just to let you know. Invade the Watermelon Field is glitched which means you can't complete it.