LSX JAP LESSON6

Well, 1 stuffed verbs ends with -eru or -iru. To build the -masu form you just have to replace the ru with masu. 5 stuffed verbs are build similar. They end with -u and sometimes with a vocal or consonant before. Like utau (singing) or kaku (drawing). And sometimes (Well shit this means you have to learn more KappaR) they look like 1 stuffed verbs. You have to learn which of them are 1 or 5 stuffed.
[16:25:57] Hatsune Miku desu: In every stage of the 5 stuffed verbs you have to change the last u with another vocal.

Lets take drawing as example.
[16:31:11] Hatsune Miku desu: かく kaku drawing infinitive
か化 kaka drawing a-step
書き kaki drawing i-step
かく kaku drawing u-step
かけ kake drawing e-step
かこう kakou(!) drawing o-step.

As you can see you just have to change the last letter in every step.
The u-step is the same as the infinitive. But in the last step, the o step, you have to put in a "ou"