diff --git a/proto/anki/decks.proto b/proto/anki/decks.proto
index 21973cce3..a1be6627c 100644
--- a/proto/anki/decks.proto
+++ b/proto/anki/decks.proto
@@ -21,6 +21,7 @@ service DecksService {
   rpc SetDeckCollapsed(SetDeckCollapsedRequest) returns (collection.OpChanges);
   rpc GetDeckLegacy(DeckId) returns (generic.Json);
   rpc GetDeckNames(GetDeckNamesRequest) returns (DeckNames);
+  rpc GetDeckAndChildNames(DeckId) returns (DeckNames);
   rpc NewDeckLegacy(generic.Bool) returns (generic.Json);
   rpc RemoveDecks(DeckIds) returns (collection.OpChangesWithCount);
   rpc ReparentDecks(ReparentDecksRequest)
diff --git a/pylib/anki/decks.py b/pylib/anki/decks.py
index 5f2d563ab..cf7e08c8a 100644
--- a/pylib/anki/decks.py
+++ b/pylib/anki/decks.py
@@ -443,26 +443,31 @@ class DeckManager(DeprecatedNamesMixin):
     def key(cls, deck: DeckDict) -> list[str]:
         return cls.path(deck["name"])
 
-    def children(self, did: DeckId) -> list[tuple[str, DeckId]]:
-        "All children of did, as (name, id)."
-        name = self.get(did)["name"]
-        actv = []
-        for entry in self.all_names_and_ids():
-            if entry.name.startswith(f"{name}::"):
-                actv.append((entry.name, DeckId(entry.id)))
-        return actv
-
-    def child_ids(self, parent_name: str) -> Iterable[DeckId]:
-        prefix = f"{parent_name}::"
+    def deck_and_child_name_ids(self, deck_id: DeckId) -> Iterable[tuple[str, DeckId]]:
+        """The deck of did and all its children, as (name, id)."""
         return (
-            DeckId(d.id) for d in self.all_names_and_ids() if d.name.startswith(prefix)
+            (entry.name, DeckId(entry.id))
+            for entry in self.col._backend.get_deck_and_child_names(deck_id)
         )
 
+    def children(self, did: DeckId) -> list[tuple[str, DeckId]]:
+        "All children of did, as (name, id)."
+        return [
+            name_id
+            for name_id in self.deck_and_child_name_ids(did)
+            if name_id[1] != did
+        ]
+
+    def child_ids(self, parent_name: str) -> Iterable[DeckId]:
+        if not (parent_id := self.id_for_name(parent_name)):
+            return []
+        return (name_id[1] for name_id in self.children(parent_id))
+
     def deck_and_child_ids(self, deck_id: DeckId) -> list[DeckId]:
-        parent_name = self.name(deck_id)
-        out = [deck_id]
-        out.extend(self.child_ids(parent_name))
-        return out
+        return [
+            DeckId(entry.id)
+            for entry in self.col._backend.get_deck_and_child_names(deck_id)
+        ]
 
     def parents(
         self, did: DeckId, name_map: dict[str, DeckDict] | None = None
diff --git a/rslib/src/backend/decks.rs b/rslib/src/backend/decks.rs
index 026d588c9..08a7935ef 100644
--- a/rslib/src/backend/decks.rs
+++ b/rslib/src/backend/decks.rs
@@ -128,12 +128,14 @@ impl DecksService for Backend {
             } else {
                 col.get_all_normal_deck_names()?
             };
-            Ok(pb::DeckNames {
-                entries: names
-                    .into_iter()
-                    .map(|(id, name)| pb::DeckNameId { id: id.0, name })
-                    .collect(),
-            })
+            Ok(names.into())
+        })
+    }
+
+    fn get_deck_and_child_names(&self, input: pb::DeckId) -> Result<pb::DeckNames> {
+        self.with_col(|col| {
+            col.get_deck_and_child_names(input.did.into())
+                .map(Into::into)
         })
     }
 
@@ -293,6 +295,23 @@ impl From<pb::deck::Kind> for DeckKind {
     }
 }
 
+impl From<(DeckId, String)> for pb::DeckNameId {
+    fn from(id_name: (DeckId, String)) -> Self {
+        pb::DeckNameId {
+            id: id_name.0 .0,
+            name: id_name.1,
+        }
+    }
+}
+
+impl From<Vec<(DeckId, String)>> for pb::DeckNames {
+    fn from(id_names: Vec<(DeckId, String)>) -> Self {
+        pb::DeckNames {
+            entries: id_names.into_iter().map(Into::into).collect(),
+        }
+    }
+}
+
 // fn new_deck(&self, input: pb::Bool) -> Result<pb::Deck> {
 //     let deck = if input.val {
 //         Deck::new_filtered()
diff --git a/rslib/src/decks/name.rs b/rslib/src/decks/name.rs
index 6c036317f..d694c4a74 100644
--- a/rslib/src/decks/name.rs
+++ b/rslib/src/decks/name.rs
@@ -161,6 +161,15 @@ impl Collection {
             self.storage.get_all_deck_names()
         }
     }
+
+    pub fn get_deck_and_child_names(&self, did: DeckId) -> Result<Vec<(DeckId, String)>> {
+        Ok(self
+            .storage
+            .deck_with_children(did)?
+            .iter()
+            .map(|deck| (deck.id, deck.name.human_name()))
+            .collect())
+    }
 }
 
 fn invalid_char_for_deck_component(c: char) -> bool {