StringからDate型に変換できない

KotlinでString型からDate型にSimpleDateFormatを使って変換させようとしています。
String型の2018/12/18をDate型の2018/12/18に変換させたいです。
上手くフォーマットを使いこなせず、正しく変換することが出来ません。画像の値：以降のデータになってしまいます。
どなたかご教授お願いします。

class Kakeibo_AddActivity : FragmentActivity(), DatePick.Callback {
    private lateinit var realm: Realm

    private var kshushi = ""
    private var kgenre = ""

    private val sdf = SimpleDateFormat("yyyy/mm/dd", Locale.JAPAN)


    override fun onCreate(savedInstanceState: Bundle?) {

        super.onCreate(savedInstanceState)
        setContentView(R.layout.testactivity)

        val config = RealmConfiguration.Builder().deleteRealmIfMigrationNeeded().build()

        Realm.setDefaultConfiguration(config)

        realm = Realm.getDefaultInstance()

        val dateEdit = findViewById<TextView>(R.id.date)
        val moneyEdit = findViewById<EditText>(R.id.kmoney)
        val insertBtn = findViewById<Button>(R.id.insertBtn)

        or.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
            override fun onItemSelected(parent: AdapterView<*>?, view: View?, position: Int, id: Long) {
                val spinnerParent = parent as Spinner
                kshushi = spinnerParent.selectedItem as String
            }

            override fun onNothingSelected(parent: AdapterView<*>?) {
            }
        }
        genre.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
            override fun onItemSelected(parent: AdapterView<*>?, view: View?, position: Int, id: Long) {
                val spinnerParent = parent as Spinner
                kgenre = spinnerParent.selectedItem as String
            }
            override fun onNothingSelected(parent: AdapterView<*>?) {
            }
        }

        insertBtn.setOnClickListener {

            // エディットテキストのテキストを取得
            val kdateo = dateEdit.text.toString()
            val kdaten = sdf.parse(kdateo)
            val money = moneyEdit.text.toString()
            val kmoney = Integer.parseInt(money)

            realm.executeTransaction {
                val maxShushiId = realm.where<Kakeibo>().max("shushiId")
                val targetShushiId = (maxShushiId?.toLong() ?: 0L) + 1L
                val kakeibo = realm.createObject<Kakeibo>(targetShushiId)
                kakeibo.date = kdaten
                kakeibo.shushi = kshushi
                kakeibo.money = kmoney
                kakeibo.genre = kgenre
                Toast.makeText(this, "値：" + kdaten.toString(),
                    Toast.LENGTH_LONG).show()
//                Toast.makeText(
//                    this, "追加しました ID:" + targetShushiId.toString(),
//                    Toast.LENGTH_SHORT
//                ).show()
            }
        }
        var listView: ListView


        val kakeibo_navi: BottomNavigationItemView = findViewById(R.id.navigation_kakeibo)
        val resito_navi: BottomNavigationItemView = findViewById(R.id.navigation_resito)
        val buylist_navi: BottomNavigationItemView = findViewById(R.id.navigation_buylist)
        val analysis_navi: BottomNavigationItemView = findViewById(R.id.navigation_analysis)
        kakeibo_navi.setOnClickListener {
            val intent = Intent(this, kakeiboActivity::class.java)
            startActivity(intent)
        }
        buylist_navi.setOnClickListener {
            val intent = Intent(this, buylistActivity::class.java)
            startActivity(intent)
        }
        resito_navi.setOnClickListener {
            val intent = Intent(this, resitoActivity::class.java)

            startActivity(intent)
        }
        analysis_navi.setOnClickListener {
            val intent = Intent(this, MainActivity::class.java)
            startActivity(intent)
        }
    }

    override fun onDatePicked(year: Int, monthOfYear: Int, dayOfMonth: Int) {
        val str = String.format(Locale.US, "%d/%d/%d", year, monthOfYear + 1, dayOfMonth)
        date.text = str
    }

    override fun onAttachFragment(fragment: Fragment) {
        if (fragment is DatePick) {
            fragment.callback = this
        }
    }

    fun showDatePickerDialog(v: View) {
        val newFragment = DatePick()
        newFragment.show(supportFragmentManager, "datePicker")
    }

}