diff --git a/docs/en/_config.yml b/docs/en/_config.yml
index 0bd35a4e..f5ef8a33 100644
--- a/docs/en/_config.yml
+++ b/docs/en/_config.yml
@@ -44,16 +44,19 @@ launch_buttons:
   colab_url: "https://colab.research.google.com"
 
 sphinx:
+  extra_extensions:
+    - sphinxcontrib.katex
   recursive_update: true
   config:
+    mathjax_path: ""
     html_theme_options:
       show_toc_level: 5
     intersphinx_mapping:
       api_reference: [https://jij-inc-jijmodeling.readthedocs-hosted.com/en/stable/, null]
       numpy: [https://numpy.org/doc/stable, null]
-      python: ["https://docs.python.org/3", null]
+      python: ["https://docs.python.org/ja/3", "https://docs.python.org/ja/3/objects.inv"]
       ommx_api: ["https://jij-inc.github.io/ommx/python/ommx", null]
-      ommx_doc: ["https://jij-inc.github.io/ommx/en", null]
+      ommx_doc: ["https://jij-inc.github.io/ommx/ja", null]
 
 parse:
   myst_enable_extensions:
diff --git a/docs/en/_static/custom.css b/docs/en/_static/custom.css
new file mode 100644
index 00000000..8c582941
--- /dev/null
+++ b/docs/en/_static/custom.css
@@ -0,0 +1,4 @@
+div.math {
+    flex-direction: row;
+    gap: .5em;
+}
\ No newline at end of file
diff --git a/docs/ja/_config.yml b/docs/ja/_config.yml
index 2ca4952d..1c174c83 100644
--- a/docs/ja/_config.yml
+++ b/docs/ja/_config.yml
@@ -44,8 +44,11 @@ launch_buttons:
   colab_url: "https://colab.research.google.com"
 
 sphinx:
+  extra_extensions:
+    - sphinxcontrib.katex
   recursive_update: true
   config:
+    mathjax_path: ""
     html_theme_options:
       show_toc_level: 5
     intersphinx_mapping:
diff --git a/docs/ja/_static/custom.css b/docs/ja/_static/custom.css
new file mode 100644
index 00000000..8c582941
--- /dev/null
+++ b/docs/ja/_static/custom.css
@@ -0,0 +1,4 @@
+div.math {
+    flex-direction: row;
+    gap: .5em;
+}
\ No newline at end of file
diff --git a/pyproject.toml b/pyproject.toml
index 01c3f2d1..a4f7169b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -16,6 +16,7 @@ dev = [
   "jupyter-book >= 1.0.0, < 2.0.0",
   "jupytext >= 1.18.1, < 2.0.0",
   "nbconvert>=7.16.6, <8.0.0",
+  "sphinxcontrib-katex >=0.9.11, <1.0.0",
 ]
 
 [build-system]
diff --git a/uv.lock b/uv.lock
index a1faabbc..3e9fea18 100644
--- a/uv.lock
+++ b/uv.lock
@@ -529,6 +529,7 @@ dev = [
     { name = "jupyter-book" },
     { name = "jupytext" },
     { name = "nbconvert" },
+    { name = "sphinxcontrib-katex" },
 ]
 
 [package.metadata]
@@ -540,6 +541,7 @@ requires-dist = [
     { name = "ommx", specifier = ">=2.3.4,<3.0.0" },
     { name = "ommx-openjij-adapter", specifier = ">=2.3.4,<3.0.0" },
     { name = "ommx-pyscipopt-adapter", specifier = ">=2.3.4,<3.0.0" },
+    { name = "sphinxcontrib-katex", marker = "extra == 'dev'", specifier = ">=0.9.11,<1.0.0" },
 ]
 provides-extras = ["dev"]
 
@@ -1867,6 +1869,18 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/c2/42/4c8646762ee83602e3fb3fbe774c2fac12f317deb0b5dbeeedd2d3ba4b77/sphinxcontrib_jsmath-1.0.1-py2.py3-none-any.whl", hash = "sha256:2ec2eaebfb78f3f2078e73666b1415417a116cc848b72e5172e596c871103178", size = 5071, upload-time = "2019-01-21T16:10:14.333Z" },
 ]
 
+[[package]]
+name = "sphinxcontrib-katex"
+version = "0.9.11"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "sphinx" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/9a/cd/71d3c7fc1a4e40a03048ce68787e4e4b6f612dc6b95acc89f5010d4cda7a/sphinxcontrib_katex-0.9.11.tar.gz", hash = "sha256:2d32b210d20bbee451a51d19645f6fef5f5568b9a54e2813affb96efa661238a", size = 100476, upload-time = "2025-06-27T12:04:12.703Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/33/14/c62d4553dbf27156b6549ceed1a9768f801c979237a2cf0c3d074e16272f/sphinxcontrib_katex-0.9.11-py3-none-any.whl", hash = "sha256:b0a318d86b8f43314ccdd481ce0db90283ac51f51afd9479969f36a0c291f44e", size = 97956, upload-time = "2025-06-27T12:04:11.478Z" },
+]
+
 [[package]]
 name = "sphinxcontrib-qthelp"
 version = "2.0.0"