Jade Cocoon: Story of the Tamamayu ^{(PlayStation)}

Lots of Mugwort Herbs

After you meet Koris for the first time in the Beetle forest, when he says
he will train you, select "Attacks and Defense" and start training. He
will give you a Mugwort herb. During the battle, on the first, second, or
third turn ignore what Koris tells you to do and select a different command
(except item) and he will tell you that you must obey. The fight will end
and you will have an extra Mugwort Herb! You can repeat this until you
have as many herbs as you like. Unfortunately, the item maximum is 20.

Easily Beat Bird Man

To easily beat the Bird Man, use fire minions. They will make the process a lot
easier. Just in case, have plenty of Mugorts ready.