What the drug can show is probably a part of an earnest wish from deep within each person's consciousness.

Those who say it did not work likely couldn't accept that as "happiness".

Even as the ruler of dreams...

I cannot control what those I show dreams to will feel towards them.

If you've got a lot of complaints...

Why don't you try changing the drug's slogan?

...You're right.

The day after...

Eientei's butterfly pills...

Had this line added to them: Effects may vary individually