After surviving the Hoshidan attack on Dia, you arrive in Notre Sagesse.
Preparations Before the Battle
You will want to have an equal number of sword/magic users, axe/club/bow users, and lance/hidden weapon users for this battle.
When you look at the map before the battle, you will notice that the battle is going to take place in multiple rooms. You can put the cursor over the stairs and press A to see where the stairs lead.
Arrange your units so that you have sword-wielders and magic users on both the left and right sides, but concentrate your lancers and hidden weapon users on the right, while keeping your axe and bow-wielders on the left.
There are a couple of chests in this map, so bring Niles to open them up for you.
Defeat the Boss
The objective is to reach the highest room and defeat Hinoka.
In the second-highest rooms, there are chests. The one on the left contains Spirit Dust, and the one on the right contains the spell Enfeeble.
Don't let any of your units end their turns standing on stairs! This will prevent all other units from using the stairs until the next player phase.
When a unit goes up stairs, it can move a bit farther into the room afterward, depending on its movement rate (i.e. some units can only move one square farther into the room, while others can move three squares in).
Split up your units to simultaneously go up the left and right stairs. You will want to use swords and magic against the Oni Savages and Archers in both rooms. I recommend using Magic at range against the Archers, because they all have the Counter skill, which will damage anyone who uses a melee attack against them.
The units that went to the left will encounter Ninjas in the next room. They have the Lunge skill, which will cause your unit to switch places with the ninja that your unit defeated.
The units that went to the right will encounter mages in the next room. They have the Miracle skill, which gives them a chance to survive a fatal attack. Also, Azama has a Hexing Rod, which cuts the targeted unit's HP in half. In order to avoid having to heal multiple units, you can send a single unit into Azama's attack range so that it is the only one affected. Lances and Hidden Weapons are most effective against these magic-users.
After this, your units will rejoin each other in the second-to-last room, where you find three pairs of Samurai. Being sword-wielders, they are weakest to lances and hidden weapons.
At this point, you might want to send Niles to open the chests if he hasn't already.
After dealing with the paired Samurai, send your units upstairs to deal with Hinoka. The Shrine Maiden behind her will keep healing her, so you might want to bring down the Shrine Maiden before attempting to fight Hinoka. Axes and bows will be most effective against Hinoka and the Sky Knights surrounding her.