diff --git a/app/models/character.rb b/app/models/character.rb
index a8a610e..029ae10 100644
--- a/app/models/character.rb
+++ b/app/models/character.rb
@@ -34,6 +34,16 @@ class Character < ApplicationRecord
                     }
                   }
 
+  has_many :character_skills,
+           primary_key: 'granblue_id',
+           foreign_key: 'character_granblue_id'
+  has_many :skills,
+           through: :character_skills
+  has_many :charge_attacks,
+           -> { where(owner_type: 'character') },
+           primary_key: 'granblue_id',
+           foreign_key: 'owner_id'
+
   AWAKENINGS = [
     { slug: 'character-balanced', name_en: 'Balanced', name_jp: 'バランス', order: 0 },
     { slug: 'character-atk', name_en: 'Attack', name_jp: '攻撃', order: 1 },
diff --git a/app/models/summon.rb b/app/models/summon.rb
index 5989216..cf586f1 100644
--- a/app/models/summon.rb
+++ b/app/models/summon.rb
@@ -34,6 +34,15 @@ class Summon < ApplicationRecord
                     }
                   }
 
+  has_many :summon_calls,
+           primary_key: 'granblue_id',
+           foreign_key: 'summon_granblue_id'
+  has_many :summon_auras,
+           primary_key: 'granblue_id',
+           foreign_key: 'summon_granblue_id'
+  has_many :skills,
+           through: :summon_calls
+
   def blueprint
     SummonBlueprint
   end
diff --git a/app/models/weapon.rb b/app/models/weapon.rb
index 6f6e7e8..2586898 100644
--- a/app/models/weapon.rb
+++ b/app/models/weapon.rb
@@ -36,6 +36,15 @@ class Weapon < ApplicationRecord
 
   has_many :weapon_awakenings
   has_many :awakenings, through: :weapon_awakenings
+  has_many :weapon_skills,
+           primary_key: 'granblue_id',
+           foreign_key: 'weapon_granblue_id'
+  has_many :skills,
+           through: :weapon_skills
+  has_many :charge_attacks,
+           -> { where(owner_type: 'weapon') },
+           primary_key: 'granblue_id',
+           foreign_key: 'owner_id'
 
   SERIES_SLUGS = {
     1 => 'seraphic',