Direct brave from hand?

The manual say:

[D5.2] Summoning Braves
In the same way you summon a Spirit, pay the Core Cost from your Reserve or your Field to place a Brave Card from your hand to the Field. This is how you "summon a Brave." Once summoned, you must place a number of Cores from your Field or Reserve on the Brave equal to its Battle Level 1 Core Cost (stated on the card). This is its "Lv. 1 Spirit Brave" form, where it is treated as a Spirit. Braves actually double as creatures (Spirits) and fusion material; their second mechanic is somewhat similar to the Equip Spell Cards from Yu-Gi-Oh!. After summoning the Brave onto the Field, if there is a Spirit on your Field that meets the Brave's specific requirements for fusing, you can immediately perform Brave Fusion (see next segment). Any "When This Brave is Summoned" effects a Brave has activate both when first brought to the Field, and immediately after Brave Fusing with a Spirit.

The brav must be first summon in spirit mode or it can be direct brave with spirit with specific requirements?

This was a mistake in translation on my part. As UnknownKIRA kindly implied, yes, you can perform Brave Fusion with the Braves in your hand and not just the ones already summoned on the Field (as long as the Spirits in question meet the fusing conditions). I have updated Segment D5.2 with this new information.