This Paralogue is unlocked when Ryoma has obtained an S Support with a female character.
The script for this chapter can be found here.
Subjective: The following part of this article is subjective to the editor's writing. Therefore, it may not work for everyone.
This paralogue can be significantly harder compared to the other children paralogues. To start off, Shiro is in the middle of the map surrounded by hostile promoted units which are far more powerful than he is. If you tackle this paralogue very late, the enemies will be capable of doubling him easily. To make matters worse, Shiro will most likely suicide onto a nearby unit which will prevent the player from recruiting him.
There are very few ways to reach Shiro in one turn; either by ferrying Ryoma with multiple fliers, using several rescue staves to warp him next to Ryoma, or (probably the most reliable): pair up a Rescue staff user with a Flier and Ryoma with another, place said staff user/flier duet as close as possible to Shiro, switch them to use the staff on him, and then use a similar tactic to place Ryoma close enough to talk to Shiro and recruit him.
Remember that if Shiro is defeated before Ryoma is able to talk to him, he will be unrecruitable (essentially wasting the paralogue). If attempted on Chapter 26, you must rescue Shiro immediately as nearest enemy close to him will kill him at the end of the turn. Make sure that you deal with the clump of enemies next to your starting position first to avoid any unnecessary casualties.
The enemy units in this chapter consist of Master Ninjas, Sorcerers, Berserkers, Heroes and Adventurers. Tarba sits in the far top right corner of the map with a Killer Axe surrounded by two units; it is advised to lure his guards out so he can be dealt without hassle from the other enemies. He has a relatively large amount of health but the Berserker's poor defensive growths means that he can be easily taken out in one or two turns.
The Dragon Vein makes an appearance in this chapter; when used it will turn patches of desert into grass tiles which will remove the move restriction that desert tiles normally have on non-magical/mounted units.