diff --git a/denops/@denops-private/plugin/naive/denops.ts b/denops/@denops-private/plugin/naive/denops.ts
new file mode 100644
index 00000000..6119a111
--- /dev/null
+++ b/denops/@denops-private/plugin/naive/denops.ts
@@ -0,0 +1,80 @@
+import { ensure, is } from "https://deno.land/x/unknownutil@v3.10.0/mod.ts";
+import {
+  BatchError,
+  Context,
+  Denops,
+  Dispatcher,
+  Meta,
+} from "../../../@denops/mod.ts";
+import type { Service } from "../../service.ts";
+
+const isBatchReturn = is.TupleOf([is.Array, is.String] as const);
+
+export class DenopsImpl implements Denops {
+  readonly context: Record<string | number | symbol, unknown> = {};
+  readonly name: string;
+  dispatcher: Dispatcher = {};
+  #service: Service;
+
+  constructor(
+    name: string,
+    service: Service,
+  ) {
+    this.name = name;
+    this.#service = service;
+  }
+
+  get meta(): Meta {
+    return this.#service.meta;
+  }
+
+  redraw(force?: boolean): Promise<void> {
+    return this.#service.host.redraw(force);
+  }
+
+  call(fn: string, ...args: unknown[]): Promise<unknown> {
+    return this.#service.host.call(fn, ...normArgs(args));
+  }
+
+  batch(
+    ...calls: [string, ...unknown[]][]
+  ): Promise<unknown[]> {
+    const normCalls = calls.map(([fn, ...args]) =>
+      [fn, ...normArgs(args)] as const
+    );
+    return this.#service.host.batch(...normCalls).then((ret) => {
+      const [results, errmsg] = ensure(ret, isBatchReturn);
+      if (errmsg !== "") {
+        throw new BatchError(errmsg, results);
+      }
+      return results;
+    });
+  }
+
+  cmd(cmd: string, ctx: Context = {}): Promise<void> {
+    return this.#service.host.call("denops#api#cmd", cmd, ctx).then();
+  }
+
+  eval(expr: string, ctx: Context = {}): Promise<unknown> {
+    return this.#service.host.call("denops#api#eval", expr, ctx);
+  }
+
+  dispatch(
+    name: string,
+    fn: string,
+    ...args: unknown[]
+  ): Promise<unknown> {
+    return this.#service.dispatch(name, fn, args);
+  }
+}
+
+function normArgs(args: unknown[]): unknown[] {
+  const normArgs = [];
+  for (const arg of args) {
+    if (arg === undefined) {
+      break;
+    }
+    normArgs.push(arg);
+  }
+  return normArgs;
+}
diff --git a/denops/@denops-private/plugin/naive/denops_test.ts b/denops/@denops-private/plugin/naive/denops_test.ts
new file mode 100644
index 00000000..ea452290
--- /dev/null
+++ b/denops/@denops-private/plugin/naive/denops_test.ts
@@ -0,0 +1,221 @@
+import * as path from "https://deno.land/std@0.208.0/path/mod.ts";
+import {
+  assertEquals,
+  assertRejects,
+} from "https://deno.land/std@0.208.0/assert/mod.ts";
+import { test } from "https://deno.land/x/denops_test@v1.4.0/mod.ts";
+import { BatchError } from "../../../@denops/mod.ts";
+
+test({
+  mode: "all",
+  name: "impl",
+  fn: async (denops, t) => {
+    await t.step({
+      name: "denops.redraw() does nothing",
+      fn: async () => {
+        assertEquals(
+          await denops.redraw(),
+          undefined,
+        );
+
+        assertEquals(
+          await denops.redraw(true),
+          undefined,
+        );
+
+        assertEquals(
+          await denops.redraw(false),
+          undefined,
+        );
+      },
+    });
+
+    await t.step({
+      name: "denops.call() calls a Vim/Neovim function and return a result",
+      fn: async () => {
+        assertEquals(
+          await denops.call("range", 10),
+          [0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
+        );
+      },
+    });
+
+    await t.step({
+      name: "denops.call() calls a Vim/Neovim function and throw an error",
+      fn: async () => {
+        await assertRejects(
+          async () => {
+            await denops.call("no-such-function");
+          },
+          "E117: Unknown function: no-such-function",
+        );
+      },
+    });
+
+    await t.step({
+      name:
+        "denops.call() drop arguments after `undefined` (but `null`) for convenience",
+      fn: async () => {
+        assertEquals(
+          await denops.call("denops#api#id", 0, 1, 2),
+          [0, 1, 2],
+        );
+        assertEquals(
+          await denops.call("denops#api#id", 0, 1, undefined, 2),
+          [0, 1],
+        );
+        assertEquals(
+          await denops.call("denops#api#id", 0, undefined, 1, 2),
+          [0],
+        );
+        assertEquals(
+          await denops.call("denops#api#id", 0, 1, null, 2),
+          [0, 1, null, 2],
+        );
+        assertEquals(
+          await denops.call("denops#api#id", 0, null, 1, 2),
+          [0, null, 1, 2],
+        );
+      },
+    });
+
+    await t.step({
+      name: "denops.cmd() invoke a Vim/Neovim command",
+      fn: async () => {
+        await denops.cmd("execute 'let g:denops_test = value'", {
+          value: "Hello World",
+        });
+        assertEquals(
+          await denops.eval("g:denops_test") as string,
+          "Hello World",
+        );
+      },
+    });
+
+    await t.step({
+      name: "denops.cmd() invoke a Vim/Neovim command and throw an error",
+      fn: async () => {
+        await assertRejects(
+          async () => {
+            await denops.cmd("NoSuchCommand");
+          },
+          "E492: Not an editor command: NoSuchCommand",
+        );
+      },
+    });
+
+    await t.step({
+      name:
+        "denops.eval() evaluate a Vim/Neovim expression and return a result",
+      fn: async () => {
+        await denops.cmd("execute 'let g:denops_test = value'", {
+          value: "Hello World",
+        });
+        assertEquals(
+          await denops.eval("g:denops_test") as string,
+          "Hello World",
+        );
+      },
+    });
+
+    await t.step({
+      name: "denops.eval() evaluate a Vim/Neovim expression and throw an error",
+      fn: async () => {
+        await assertRejects(
+          async () => {
+            await denops.eval("g:no_such_variable");
+          },
+          "g:no_such_variable",
+          // Vim:    "E15: Invalid expression: g:no_such_variable",
+          // Neovim: "E121: Undefined variable: g:no_such_variable",
+        );
+      },
+    });
+
+    await t.step({
+      name:
+        "denops.batch() calls multiple Vim/Neovim functions and return results",
+      fn: async () => {
+        const results = await denops.batch(["range", 1], ["range", 2], [
+          "range",
+          3,
+        ]);
+        assertEquals(results, [[0], [0, 1], [0, 1, 2]]);
+      },
+    });
+
+    await t.step({
+      name:
+        "denops.batch() calls multiple Vim/Neovim functions and throws an error with results",
+      fn: async () => {
+        await assertRejects(async () => {
+          await denops.batch(
+            ["range", 1],
+            ["no-such-function", 2],
+            ["range", 3],
+          );
+        }, BatchError);
+      },
+    });
+
+    await t.step({
+      name:
+        "denops.batch() drop arguments after `undefined` (but `null`) for convenience",
+      fn: async () => {
+        const results = await denops.batch(
+          ["denops#api#id", 0, 1, 2],
+          ["denops#api#id", 0, 1, undefined, 2],
+          ["denops#api#id", 0, undefined, 1, 2],
+          ["denops#api#id", 0, 1, null, 2],
+          ["denops#api#id", 0, null, 1, 2],
+        );
+        assertEquals(results, [[0, 1, 2], [0, 1], [0], [0, 1, null, 2], [
+          0,
+          null,
+          1,
+          2,
+        ]]);
+      },
+    });
+
+    await t.step({
+      name: "denops.call() works properly even when called concurrently",
+      fn: async () => {
+        const cwd = await denops.call("getcwd") as string;
+        await denops.cmd("edit dummy1");
+        await denops.cmd("file dummy2");
+        const results = await Promise.all([
+          denops.call("expand", "%"),
+          denops.call("expand", "%:p"),
+          denops.call("expand", "%hello"),
+          denops.call("expand", "#"),
+          denops.call("expand", "#:p"),
+          denops.call("expand", "#hello"),
+        ]);
+        assertEquals(results, [
+          "dummy2",
+          path.join(cwd, "dummy2"),
+          "dummy2",
+          "dummy1",
+          path.join(cwd, "dummy1"),
+          "dummy1",
+        ]);
+      },
+    });
+
+    await t.step({
+      name: "denops.dispatch() invokes APIs of the plugin",
+      fn: async () => {
+        denops.dispatcher = {
+          hello(name: unknown): Promise<unknown> {
+            return Promise.resolve(`Hello ${name}`);
+          },
+        };
+        assertEquals(
+          await denops.dispatch(denops.name, "hello", "denops"),
+          "Hello denops",
+        );
+      },
+    });
+  },
+});
diff --git a/denops/@denops-private/plugin/naive/plugin.ts b/denops/@denops-private/plugin/naive/plugin.ts
new file mode 100644
index 00000000..44d5729e
--- /dev/null
+++ b/denops/@denops-private/plugin/naive/plugin.ts
@@ -0,0 +1,43 @@
+import type { Service } from "../../service.ts";
+import type { Plugin } from "../base.ts";
+import type { Denops, Dispatcher } from "../../../@denops/mod.ts";
+import { DenopsImpl } from "./denops.ts";
+
+export class NaivePlugin implements Plugin {
+  #denops: DenopsImpl;
+
+  readonly name: string;
+  readonly script: string;
+
+  dispatcher: Dispatcher = {};
+
+  constructor(name: string, script: string, service: Service) {
+    this.name = name;
+    this.script = script;
+    this.#denops = new DenopsImpl(name, service);
+    const suffix = `#${performance.now()}`;
+    import(`${script}${suffix}`).then(async (mod) => {
+      try {
+        await emit(this.#denops, `DenopsSystemPluginPre:${name}`);
+        await mod.main(this.#denops);
+        await emit(this.#denops, `DenopsSystemPluginPost:${name}`);
+      } catch (e) {
+        console.error(e);
+        await emit(this.#denops, `DenopsSystemPluginFail:${name}`);
+      }
+    });
+  }
+
+  async call(fn: string, ...args: unknown[]): Promise<unknown> {
+    return await this.#denops.dispatcher[fn](...args);
+  }
+
+  dispose(): void {
+    // Do nothing
+  }
+}
+
+function emit(denops: Denops, name: string): Promise<void> {
+  return denops.cmd(`doautocmd <nomodeline> User ${name}`)
+    .catch((e) => console.warn(`Failed to emit ${name}: ${e}`));
+}