diff --git a/src/entity/character.rs b/src/entity/character.rs
index 00631bb..c10bffd 100644
--- a/src/entity/character.rs
+++ b/src/entity/character.rs
@@ -173,7 +173,7 @@ impl CharacterTechniques {
     }
 
     pub fn set_tech(&mut self, tech: Technique, level: TechLevel) {
-        self.techs.insert(tech, level);
+        self.techs.insert(tech, TechLevel(level.0 - 1));
     }
 
     // from_bytes
@@ -182,7 +182,7 @@ impl CharacterTechniques {
         self.techs.iter()
             .fold([0xFF; 20], |mut techlist, (tech, level)| {
                 let index = tech.as_value();
-                techlist[index as usize] = level.0 - 1;
+                techlist[index as usize] = level.0;
                 techlist
             })
     }
diff --git a/src/ship/items/manager.rs b/src/ship/items/manager.rs
index 3a76284..07c4005 100644
--- a/src/ship/items/manager.rs
+++ b/src/ship/items/manager.rs
@@ -2,7 +2,7 @@ use crate::ship::items::ClientItemId;
 use std::collections::{HashMap, BTreeMap};
 use thiserror::Error;
 use crate::entity::gateway::EntityGateway;
-use crate::entity::character::{CharacterEntity, CharacterEntityId};
+use crate::entity::character::{CharacterEntity, CharacterEntityId, TechLevel};
 use crate::entity::item::{ItemDetail, ItemLocation, BankName};
 use crate::entity::item::{Meseta, NewItemEntity, ItemEntity, InventoryItemEntity, EquippedEntity, InventoryEntity, BankItemEntity, BankEntity};
 use crate::entity::item::tool::{Tool, ToolType};
@@ -490,13 +490,18 @@ impl ItemManager {
 
     pub async fn player_consumes_tool<EG: EntityGateway>(&mut self,
                                                          entity_gateway: &mut EG,
-                                                         character: &CharacterEntity,
+                                                         character: &mut CharacterEntity,
                                                          item_id: ClientItemId,
                                                          amount: usize)
                                                          -> Result<ConsumedItem, ItemManagerError> {
         let inventory = self.character_inventory.get_mut(&character.id).ok_or(ItemManagerError::NoCharacter(character.id))?;
         let used_item = inventory.get_item_handle_by_id(item_id).ok_or(ItemManagerError::NoSuchItemId(item_id))?;
         let consumed_item = used_item.consume(amount)?;
+        
+        if let ItemDetail::TechniqueDisk(tech_disk) = consumed_item.item() {
+            character.techs.set_tech(tech_disk.tech, TechLevel(tech_disk.level as u8));
+            entity_gateway.save_character(character).await?;
+        };
 
         for entity_id in consumed_item.entity_ids() {
             entity_gateway.change_item_location(&entity_id,
diff --git a/src/ship/packet/handler/message.rs b/src/ship/packet/handler/message.rs
index 79ceaa5..f8a9f82 100644
--- a/src/ship/packet/handler/message.rs
+++ b/src/ship/packet/handler/message.rs
@@ -261,7 +261,7 @@ where
     EG: EntityGateway
 {
     let client = clients.get_mut(&id).ok_or(ShipError::ClientNotFound(id))?;
-    let item_used_type = item_manager.player_consumes_tool(entity_gateway, &client.character, ClientItemId(player_use_tool.item_id), 1).await?;
+    let item_used_type = item_manager.player_consumes_tool(entity_gateway, &mut client.character, ClientItemId(player_use_tool.item_id), 1).await?;
 
     item_manager.use_item(item_used_type, entity_gateway, &mut client.character).await?;
     Ok(Box::new(None.into_iter()))
diff --git a/tests/test_item_use.rs b/tests/test_item_use.rs
index 8a51875..03cb935 100644
--- a/tests/test_item_use.rs
+++ b/tests/test_item_use.rs
@@ -266,3 +266,20 @@ async fn test_use_materials() {
     assert!(char.materials.luck == 2);
 }
 
+#[async_std::test]
+pub async fn test_learn_new_tech() {}
+
+#[async_std::test]
+pub async fn test_new_fo_has_foie_1() {}
+
+#[async_std::test]
+pub async fn test_char_cannot_use_lower_level_tech() {}
+
+#[async_std::test]
+pub async fn test_char_cannot_learn_wrong_tech() {}
+
+#[async_std::test]
+pub async fn test_char_cannot_learn_high_level_tech() {}
+
+#[async_std::test]
+pub async fn test_android_cannot_learn_tech() {}
\ No newline at end of file