diff --git a/src/content/post/placeholder1.md b/src/content/post/placeholder1.md
index ec423d5..72a5f65 100644
--- a/src/content/post/placeholder1.md
+++ b/src/content/post/placeholder1.md
@@ -3,6 +3,7 @@ title: Placeholder 1
 date: '2024-09-01'
 description: "This is a placeholder description"
 tags: ["a123", "ボースト"]
+series: ["placeholder"]
 ---
 # 1st Level Heading
 
diff --git a/src/content/post/placeholder2.md b/src/content/post/placeholder2.md
new file mode 100644
index 0000000..356955e
--- /dev/null
+++ b/src/content/post/placeholder2.md
@@ -0,0 +1,8 @@
+---
+title: Placeholder 2
+date: '2024-09-20'
+description: "This is a placeholder description"
+tags: ["a123"]
+series: ["placeholder"]
+---
+## Content
diff --git a/src/content/post/placeholder3.md b/src/content/post/placeholder3.md
new file mode 100644
index 0000000..52bf7b5
--- /dev/null
+++ b/src/content/post/placeholder3.md
@@ -0,0 +1,8 @@
+---
+title: Placeholder 3
+date: '2024-09-24'
+description: "This is a placeholder description"
+tags: []
+series: ["placeholder"]
+---
+## Content
diff --git a/src/content/post/the-perfect-math-class.md b/src/content/post/the-perfect-math-class.md
new file mode 100644
index 0000000..e1d3717
--- /dev/null
+++ b/src/content/post/the-perfect-math-class.md
@@ -0,0 +1,6 @@
+---
+title: The Perfect Math Class
+date: '2024-09-15'
+tags: ["Cirno"]
+---
+# Content