diff --git a/db/migrate/20251215173625_remap_character_season_values.rb b/db/migrate/20251215173625_remap_character_season_values.rb
new file mode 100644
index 0000000..a6fcd04
--- /dev/null
+++ b/db/migrate/20251215173625_remap_character_season_values.rb
@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+# Remap character season values after removing "Standard" season.
+# Old values: Standard=1, Valentine=2, Formal=3, Summer=4, Halloween=5, Holiday=6
+# New values: Valentine=1, Formal=2, Summer=3, Halloween=4, Holiday=5
+#
+# Uses negative temporary values to avoid conflicts during remapping.
+class RemapCharacterSeasonValues < ActiveRecord::Migration[8.0]
+  def up
+    # First, remap all values to negative temporaries to avoid conflicts
+    execute "UPDATE characters SET season = -2 WHERE season = 2"  # Valentine -> temp
+    execute "UPDATE characters SET season = -3 WHERE season = 3"  # Formal -> temp
+    execute "UPDATE characters SET season = -4 WHERE season = 4"  # Summer -> temp
+    execute "UPDATE characters SET season = -5 WHERE season = 5"  # Halloween -> temp
+    execute "UPDATE characters SET season = -6 WHERE season = 6"  # Holiday -> temp
+
+    # Remove Standard (1 -> NULL)
+    execute "UPDATE characters SET season = NULL WHERE season = 1"
+
+    # Now remap from temporaries to final values
+    execute "UPDATE characters SET season = 1 WHERE season = -2"  # Valentine: 2 -> 1
+    execute "UPDATE characters SET season = 2 WHERE season = -3"  # Formal: 3 -> 2
+    execute "UPDATE characters SET season = 3 WHERE season = -4"  # Summer: 4 -> 3
+    execute "UPDATE characters SET season = 4 WHERE season = -5"  # Halloween: 5 -> 4
+    execute "UPDATE characters SET season = 5 WHERE season = -6"  # Holiday: 6 -> 5
+  end
+
+  def down
+    # Remap back to original values using negative temporaries
+    execute "UPDATE characters SET season = -1 WHERE season = 1"  # Valentine -> temp
+    execute "UPDATE characters SET season = -2 WHERE season = 2"  # Formal -> temp
+    execute "UPDATE characters SET season = -3 WHERE season = 3"  # Summer -> temp
+    execute "UPDATE characters SET season = -4 WHERE season = 4"  # Halloween -> temp
+    execute "UPDATE characters SET season = -5 WHERE season = 5"  # Holiday -> temp
+
+    # Remap to original values (Standard cannot be restored from NULL)
+    execute "UPDATE characters SET season = 2 WHERE season = -1"  # Valentine: 1 -> 2
+    execute "UPDATE characters SET season = 3 WHERE season = -2"  # Formal: 2 -> 3
+    execute "UPDATE characters SET season = 4 WHERE season = -3"  # Summer: 3 -> 4
+    execute "UPDATE characters SET season = 5 WHERE season = -4"  # Halloween: 4 -> 5
+    execute "UPDATE characters SET season = 6 WHERE season = -5"  # Holiday: 5 -> 6
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index dcee9c3..cf321d7 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2025_12_14_104721) do
+ActiveRecord::Schema[8.0].define(version: 2025_12_15_173625) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "btree_gin"
   enable_extension "pg_catalog.plpgsql"